On Monday, Spotify announced a new initiative that offers artists the chance to pay their way into automated recommendations. Gizmodo reports: In a carefully worded blog post, Spotify is framing its latest move as a test that will give artists more "input" into the recommendation algorithms that populate personalized playlists with fresh tracks. The company writes that its algorithms take "into account thousands of types of signals: what you're listening to and when, which songs you're adding to your playlists, the listening habits of people who have similar tastes, and much more." Today, Spotify is adding a new signal to the mix: $$$.

Artists uploading new tracks to Spotify will be able to choose "music that's a priority for them" and in exchange for accepting a "promotional recording royalty rate," Spotify's algorithms might just bless them with exposure. The company isn't making promises, it's only offering an opportunity. There's no guarantee of placement in playlists and the reduced royalty rate is only applied to songs that end up being served through the new recommendation system. What is a "promotional recording royalty rate," exactly? [A] spokesperson for the service told the Verge that they aren't making the rate public while it's in testing and Spotify will "calibrate to make sure that the widest group of artists and labels can find success."

An RIAA takedown request, which removed the YouTube-DL repository from GitHub, has ticked off developers and GitHub's CEO. Numerous people responded by copying and republishing the contested code, including in some quite clever ways. Meanwhile, GitHub's CEO is "annoyed" as well, offering help to get the repo reinstated. TorrentFreak reports: Soon after the RIAA notice took YouTube-DL offline many developers spoke out in protest. They believe that the music industry group went too far and started to republish copies of the code everywhere. Over the past several days, we have seen hundreds of new forks and copies appear online. These were also posted to GitHub, where YouTube-DL forks remain easy to find and continue to be uploaded. The code was also posted in some places one wouldn't expect. For example, there's still a copy in GitHub's DMCA notice repository, which some people find quite amusing. And the list of pull requests can be quite entertaining in themselves.

One of the most creative responses we've seen was posted to Twitter by @GalacticFurball who encoded YouTube-DL into images that can be easily shared, encouraging others to share these as well. "I would also suggest that you save and repost the images, as one single source kind of defeats the point. Maybe start a hashtag trend or something. Make songs, and poetry. Get that data out there." This triggered even more creativity, with people finding alternative means to share the code online, all to counter the RIAA's takedown request.

Meanwhile, GitHub's CEO Nat Friedman wasn't sitting still either. While the Microsoft-owned developer platform had to respond to the takedown notice, Friedman himself actively reached out to YouTube-DL's developers to help them get their project reinstated. The CEO joined YouTube-DL's IRC channel hoping to connect with the owner of the repository so he can help to get it unsuspended. "GitHub exists to help developers. We never want to interfere with their work. We want to help the youtube-dl maintainers defeat the DMCA claim so that we can restore the repo," Friedman told TorrentFreak, explaining his actions. GitHub's CEO suggested that YouTube-DL won't be reinstated in its original form. But, the software may be able to return without the rolling cipher circumvention code and the examples of how to download copyrighted material.

Marketplace reports: Songwriter Tom Lehrer became a star in the 1950s and '60s writing and performing satirical songs that skewered just about everything... Lehrer, 92, announced Tuesday via his website that he's effectively putting everything he ever wrote into the public domain. That means his lyrics and sheet music are available for anyone to use or perform, without having to pay royalties or deal with lawyers... [Most of Lehrer's music "will be added gradually later with further disclaimers," according to Lehrer's web site.]

Lehrer's giving up those royalties. But in exchange, he's trying to give his work a new lease on life, said Siva Vaidhyanathan, a media studies professor at the University of Virginia. "Lehrer, in this case, is basically saying, 'Hey everybody, come revisit my material, come do with it what you want,'" he said... That could mean we'll be hearing more of Tom Lehrer's work, said Jennifer Jenkins, who runs the Center for the Study of the Public Domain at Duke Law School. "There is empirical research showing that when material enters the public domain, it actually gets used more," she said.
Lehrer's lyrics touched on geeky subjects including nuclear weapons, Wernher von Braun, and one song where he set the names of the chemical elements to a tune by Gilbert and Sullivan.

Wikipedia notes he "largely retired" in the 1970s to become a mathematics teacher at the University of California, Santa Cruz (also teaching the history of musical theatre). In the same decade he also wrote ten songs for The Electric Company, an educational TV show about reading broadcast on America's public television, singing two of the songs himself — L-Y and Silent E.

Apple has launched Apple Music TV, a free 24-hour curated livestream of popular music videos that will also include "exclusive new music videos and premiers, special curated music video blocks, and live shows and events as well as chart countdowns and guests," according to the announcement. From a report: Apple Music TV will be available to U.S. residents only on the Apple Music app and the Apple TV app. It can be found at apple.co/AppleMusicTV and in the browse tab in the Apple Music and Apple TV app. The service premiered Monday morning with a countdown of the top 100 all-time most-streamed songs in the U.S. on Apple Music. On Thursday (October 22), it will celebrate the upcoming release of Bruce Springsteens's "Letter to You" album with an "all day Bruce takeover" featuring music-video blocks of his most popular videos, an interview with Zane Lowe, anchor of Apple Music's radio station, and a special livestream fan event.

A remarkable first-person story in today's Washington Post: I used to call it the "scamdemic." I thought it was an overblown media hoax. I made fun of people for wearing masks. I went all the way down the rabbit hole and fell hard on my own sword, so if you want to hate me or blame me, that's fine. I'm doing plenty of that myself.

The party was my idea. That's what I can't get over. Well, I mean, it wasn't even a party — more like a get-together. There were just six of us, OK? My parents, my partner, and my partner's parents... Some people in my family didn't necessarily share all of my views, but I pushed it. I've always been out front with my opinions. I'm gay and I'm conservative, so either way I'm used to going against the grain... I told my family: "Come on. Enough already. Let's get together and enjoy life for once." They all came for the weekend. We agreed not to do any of the distancing or worry much about it... We cooked nice meals. We watched a few movies. I played a few songs on my baby grand piano. We drove to a lake about 60 miles outside of Dallas and talked and talked. It was nothing all that special. It was great. It was normal...

I have no idea which one of us brought the virus into the house, but all six of us left with it. It kept spreading from there.... I was sweating profusely. I would wake up in a pool of sweat. I had this tingling feeling all over my body, this radiating kind of pain... Then one day I was walking up the stairs, and all of the sudden, I couldn't breathe. I screamed and fell flat on my face. I blacked out. I woke up a while later in the ER, and 10 doctors were standing around me in a circle. I was lying on the table after going through a CT scan. The doctors told me the virus had attacked my nervous system. They'd given me some medications that stopped me from having a massive stroke. They said I was minutes away.

I stayed in the hospital for three days, trying to get my mind around it. It was guilt, embarrassment, shame. I thought: "OK. Maybe now I've paid for my mistake." But it kept getting worse. Six infections turned into nine. Nine went up to 14. It spread from one family member to the next, and it was like each person caught a different strain... My father is 78, and he went to get checked out at the hospital, but for whatever reasons, he seemed to recover really fast. My father-in-law nearly died in his living room and then ended up in the same hospital as me on the exact same day. His mother was in the room right next to him because she was having trouble breathing. They were lying there on both sides of the wall, fighting the same virus, and neither of them ever knew the other one was there. She died after a few weeks. On the day of her funeral, five more family members tested positive...

They put my father-in-law on a ventilator, and he lay there on life support for six or seven weeks. There was never any goodbye. He was just gone. It's like the world swallowed him up.

We could only have 10 people at the funeral, and I didn't make that list.

Spotify has rolled out a useful new feature today for iOS and Android that allows users to search for songs by its lyrics. 9to5Mac reports: When you're not sure the name of a song/artist, music recognition apps like Shazam are great if a song is playing. However, they don't work near as well if you're just trying to sing a couple of the lyrics into your phone. In those cases, it's common to search the web for the lyrics before heading to your music service to play or add the track. Now Spotify has simplified that problem as the service on both iOS and Android has added the handy option to type in lyrics to search for songs. Spotify designer Lina shared the news on Twitter this morning.

Amazon has teamed up with Universal Music and Warner Music to remaster thousands of popular streaming tracks to better-than-CD audio quality [Editor's note: the link may be paywalled; alternative source], as the music industry tries to lure listeners to pricier subscriptions. From a report: In addition to a standard $10 a month streaming service comparable to Spotify, Amazon offers a high-definition option that delivers songs to smartphones at CD sound quality or better. This service costs $15 a month, or $13 a month for members of its Prime shipping programme. The ecommerce group has spent the past year working to boost its pricier streaming service with albums from stars including Lady Gaga, Nirvana, Ariana Grande and Bob Marley in what it calls "ultra high-definition." To do so, Universal Music went back to the original recordings of albums such as Diana Ross and Marvin Gaye's Diana & Marvin and worked with sound engineers to remaster them. Amazon says the audio will "reveal nuances that were once flattened in files compressed for digital streaming or CD manufacturing." The move comes as the inflow of cash from music streaming has slowed over the past year as the market matures

"Every musician knows that when the performers can hear one another, the performance is always better than otherwise," writes Slashdot reader nightcats. "This principle applies in nature as well, and has been anecdotally witnessed amid the quiet imposed by COVID-19 on cities around the world. In San Francisco, behavioral ecologist Liz Derryberry has been able to deliver a dramatic scientific demonstration of the changes to the songs of the white-crowned sparrow amid the quiet of 2020." National Geographic reports: With most San Franciscans staying at home due to the coronavirus pandemic, she decided to seize an unprecedented opportunity to study how this small, scrappy songbird responded when human noises disappeared. By recording the species' calls among the abandoned streets of the Bay Area in the following months, Derryberry and colleagues have revealed that the shutdown dramatically improved the birds' calls, both in quality and efficiency. The research, published today in Science, is among the first to scientifically evaluate the effects of the pandemic on urban wildlife. It also adds to a burgeoning field of research into how the barrage of human-made noise has disrupted nature, from ships drowning out whale songs to automobile traffic jamming bat sonar.

Georgia Tech researcher Mark Riedl didn't expect that his machine learning model "Weird A.I. Yankovic," which generates new rhyming lyrics for existing songs would cause any trouble. But it did. From a report: On May 15, Reidl posted an AI-generated lyric video featuring the instrumental to Michael Jackson's "Beat It." It was taken down on July 14, Reidl tweeted, after Twitter received a Digital Millennium Copyright Act takedown notice for copyright infringement from the International Federation of the Phonographic Industry, which represents major and independent record companies. "I am fairly convinced that my videos fall under fair use," Riedl told Motherboard of his AI creation, which is obviously inspired by Weird Al's parodies. Riedl said his other AI-generated lyric videos posted to Twitter have not been taken down.

Riedl has contested the takedown with Twitter but has not received a response. Twitter also did not respond to Motherboard's request for comment. The incident raises the question of what role machine learning plays when it comes to the already nuanced and complicated rules of fair use, which allows for the use of a copyrighted work in certain circumstances, including educational uses and as part of a "transformative" work. Fair use also protects parody in some circumstances. Riedl, whose research focuses on the study of artificial intelligence and storytelling for entertainment, says the model was created as a personal project and outside his role at Georgia Tech. "Weird A.I. Yankovic generates alternative lyrics that match the rhyme and syllables schemes of existing songs. These alternative lyrics can then be sung to the original tune," Riedl said. "Rhymes are chosen, and two neural networks, GPT-2 and XLNET, are then used to generate each line, word by word."

"Playing with GPT-3 feels like seeing the future," Arram Sabeti, a San Francisco-based developer and artist, tweeted last week. That pretty much sums up the response on social media in the last few days to OpenAI's latest language-generating AI. From a report: OpenAI first described GPT-3 in a research paper published in May. But last week it began drip-feeding the software to selected people who requested access to a private beta. For now, OpenAI wants outside developers to help it explore what GPT-3 can do, but it plans to turn the tool into a commercial product later this year, offering businesses a paid-for subscription to the AI via the cloud. GPT-3 is the most powerful language model ever. Its predecessor, GPT-2, released last year, was already able to spit out convincing streams of text in a range of different styles when prompted with an opening sentence. But GPT-3 is a big leap forward. The model has 175 billion parameters (the values that a neural network tries to optimize during training), compared with GPT-2's already vast 1.5 billion. And with language models, size really does matter.

Sabeti linked to a blog post where he showed off short stories, songs, press releases, technical manuals, and more that he had used the AI to generate. GPT-3 can also produce pastiches of particular writers. Mario Klingemann, an artist who works with machine learning, shared a short story called "The importance of being on Twitter," written in the style of Jerome K. Jerome, which starts: "It is a curious fact that the last remaining form of social life in which the people of London are still interested is Twitter. I was struck with this curious fact when I went on one of my periodical holidays to the sea-side, and found the whole place twittering like a starling-cage." Klingemann says all he gave the AI was the title, the author's name and the initial "It." There is even a reasonably informative article about GPT-3 written entirely by GPT-3.

Researchers at Zhejiang University and Microsoft claim they've developed an AI system -- DeepSinger -- that can generate singing voices in multiple languages by training on data from music websites. From a report: In a paper published on the preprint Arxiv.org, they describe the novel approach, which leverages a specially-designed component to capture the timbre of singers from noisy singing data. The work -- like OpenAI's music-generating Jukebox AI -- has obvious commercial implications. Music artists are often pulled in for pick-up sessions to address mistakes, changes, or additions after a recording finishes. AI-assisted voice synthesis could eliminate the need for these, saving time and money on the part of the singers' employers.

But there's a darker side: It could also be used to create deepfakes that stand in for musicians, making it seem as though they sang lyrics they never did (or put them out of work). In what could be a sign of legal battles to come, Jay-Z's Roc Nation label recently filed copyright notices against videos that used AI to make him rap Billy Joel's "We Didn't Start the Fire." As the researchers explain, singing voices have more complicated patterns and rhythms than normal speaking voices. Synthesizing them requires information to control the duration and the pitch, which makes the task challenging. Plus, there aren't many publicly available singing training data sets, and songs used in training must be manually analyzed at the lyrics and audio level.

U.S. technology titans face a looming test of their free-speech credentials in Hong Kong as China's new national-security law for the city demands local authorities take measures to supervise and regulate its uncensored internet. From a report: Facebook and its Instagram service, Twitter and YouTube, a unit of Alphabet's Google, operate freely in the city even as they have been shut out or opted out of the mainland's tightly controlled internet, which uses the "Great Firewall" to censor information. In Hong Kong many citizens have grown accustomed to freely using their accounts to speak out on political matters, voice support for antigovernment protests, and register their anger at China's increasing sway over the city. Now the U.S. tech companies face a high-wire act, analysts say, if authorities here ask them to delete user accounts or their content. Refusal could invite Beijing's scrutiny and potentially put them at risk of legal action under the new national-security law. Complying would alienate longtime users in the city, some of whom continue to speak out on their platforms, and leave the companies open to criticism from politicians in the U.S. or U.K.

Among the tech giants, Twitter said in a statement it "has grave concerns" about the law and is "committed to protecting the people using our service and their freedom of expression." Twitter said it is reviewing the new rules, "particularly as some of the terms of the law are vague and without clear definition." Measures to better supervise the internet and foreign media were provisions tucked into China's national-security law for the city. The law criminalizes activities in four vaguely defined areas covering secession, subversion, terrorism and collusion with foreign forces. "Tech companies will absolutely receive more requests to remove information that is allegedly harmful to natural security from the relevant authorities," said Haochen Sun, a law professor at the University of Hong Kong. He said companies will face difficulties especially with borderline cases, such as potential requests to remove songs, for instance, that protesters have used in antigovernment demonstrations.

OpenAI this week released Jukebox, a machine learning framework that generates music -- including rudimentary songs -- as raw audio in a range of genres and musical styles. From a report: Provided with a genre, artist, and lyrics as input, Jukebox outputs a new music sample produced from scratch. The code and model are available on GitHub, along with a tool to explore the generated samples. Jukebox might not be the most practical application of AI and machine learning, but as OpenAI notes, music generation pushes the boundaries of generative models. Synthesizing songs at the audio level is challenging because the sequences are quite long -- a typical 4-minute song at CD quality (44 kHz, 16-bit) has over 10 million timesteps. As a result, learning the high-level semantics of music requires models to deal with very long-range dependencies.

The isolation caused by the spread of coronavirus means people are sitting inside all day streaming music, right? Actually, maybe not. At least for the most popular songs, people in some highly affected countries are streaming far fewer songs during the pandemic than before. From a report: In Italy, one of the countries hardest hit by coronavirus, the top 200 most streamed songs on Spotify within the country averaged 18.3 million total streams per day in February 2019. Since Italy's prime minister announced a national quarantine on March 9th, the total streams for the 200 most popular songs have not topped 14.4 million. There was a 23% drop in top 200 streams on Tuesday March 17th compared to Tuesday, March 3rd.

[...] The trend is similar in the US. On March 17th, total Spotify streams of top 200 songs fell to 77 million streams. This was the lowest number of top-200 streams in the US for any Tuesday in 2020, and about 14 million streams fewer than just a week before. Total top-200 streams are also down in the UK, France, and Spain as well.

TikTok, the hugely popular social media app, found a lot of early traction by giving users a way to create funny lip-synced versions of clips from well-known songs and then share them with friends (its predecessor in the West was even called Musically). Now at long last, TikTok's owner, China's ByteDance, is doubling down on the music connection with the release of its first standalone full music streaming app, starting first in India. From a report: Today, the company is launching Resso, which describes itself as a "social music streaming app": users are encouraged to share lyrics, comments and other user-generated content with each other, alongside full-length tracks of music that they can consume and also share with others. And the music begins to auto-play as soon as you open the app. Unlike its sister app TikTok, which is free to use and is built on an ad-based model, Resso is following the freemium route that a number of other big music apps, such as Spotify, have taken. A free tier includes ads and limits streaming quality to 128 Kbps; a premium, ad-free tier boosts streaming to 256 Kbps, includes downloads and the ability to skip tracks and costs INR 99/month ($1.35/month) on Android and INR 119/month ($1.62) on iOS.

Around the world, the most popular tunes this month will be depressing ones [Editor's note: the link may be paywalled.]. From a report: Residents of the northern hemisphere might think that their moods are worst in January. Christmas is over, the nights are long and summer is a distant prospect. Newspapers often claim that "Blue Monday," in the third week of January, is the most depressing day. To create a quantitative measure of seasonal misery, The Economist has analysed music consumption. Our calculations use data from Spotify, which offers 50m tracks to 270m users in over 70 countries, mostly in Europe and the Americas. The firm has an algorithm that classifies a song's "valence," or how happy it sounds, on a scale from 0 to 100. The algorithm is trained on ratings of positivity by musical experts, and gives Aretha Franklin's soaring "Respect" a score of 97; Radiohead's gloomy "Creep" gets just 10.

Since 2017 Spotify has also published daily tables of the 200 most-streamed songs, both worldwide and in each country. We gathered data for 30 countries around the globe, including 46,000 unique tracks with 330bn streams, to identify the annual nadir of musical mood. Drum roll, please. The global top 200 songs are gloomiest in February, when their valence is 4% lower than the annual average. In July, the perkiest month, the mood is 3% higher. The most joyful spike comes at Christmas. Strikingly, this February slump occurs in some countries near the equator, such as Singapore, and far south of it, such as Australia -- even though their musical tastes differ. A few Latin American countries lack such a dip, perhaps because the algorithm sees Latin music as mostly happy. The icy north shows the biggest seasonal swings. Finland's mood in July is 11% happier than usual. Overall, on days when a country gets one more hour of sunlight than its annual average, the valence of its streams increases by 0.6%. In contrast, wet days bring particularly downcast tunes.

"The UK has officially left the European Union after 47 years of membership," reports the BBC. The historic moment, which happened at 23:00 GMT, was marked by both celebrations and anti-Brexit protests. Candlelit vigils were held in Scotland, which voted to stay in the EU, while Brexiteers partied in London's Parliament Square... Brexit parties were held in pubs and social clubs across the UK as the country counted down to its official departure.

Hundreds gathered in Parliament Square to celebrate Brexit, singing patriotic songs and cheering speeches from leading Brexiteers, including Nigel Farage... In Northern Ireland, the campaign group Border Communities Against Brexit staged a series of protests in Armagh, near to the border with the Republic of Ireland.

At 2300 GMT, Scotland's First Minister Nicola Sturgeon tweeted a picture of the EU flag, adding: "Scotland will return to the heart of Europe as an independent country."

The U.K. flag was removed from European Union institutions in Brussels, the BBC notes. And they also quote U.K. Prime Minister Boris Johnson as saying "For all its strengths and for all its admirable qualities, the EU has evolved over 50 years in a direction that no longer suits this country."

"The most important thing to say tonight is that this is not an end but a beginning..."

A new article in Rolling Stone argues that the forgotten 2013 hit song "Blurred Lines", which a court later ruled infringed on a 1977 song by Marvin Gaye, turned copyright law into "a minefield" -- for the music industry.
While copyright laws used to protect only lyrics and melodies (a prime example is the Chiffons' successful suit against George Harrison in 1976 for the strong compositional similarities between his "My Sweet Lord" and their "He's So Fine"), the "Blurred Lines" case raised the stakes by suggesting that the far more abstract qualities of rhythm, tempo, and even the general feel of a song are also eligible for protection -- and thus that a song can be sued for feeling like an earlier one. Sure enough, a jury in 2019 ruled that Katy Perry owed millions for ostensibly copying the beat of her hit "Dark Horse" from a little-known song by Christian rapper Flame, stunning both the music business and the legal community. "They're trying to own basic building blocks of music, the alphabet of music that should be available to everyone," Perry's lawyer Christine Lepera warned in the case's closing arguments.

That case, which Perry's team is currently in the process of appealing, suggests a second point: Plaintiffs in copycat cases are largely targeting megahit songs because they've seen where the money is, and the increasing frequency of those court battles in headlines is causing an avalanche effect of further infringement lawsuits.... While some record labels may have the budget to hire on-call musicologists who vet new releases for potential copyright claims, smaller players who can't afford that luxury are turning toward a tried-and-true form of protection: insurance. Lucas Keller -- the founder of music management company Milk and Honey, which represents writers and producers who've worked with everyone from Alessia Cara and Carrie Underwood to 5 Seconds of Summer and Muse -- recently began encouraging all his songwriter clients to purchase errors-and-omissions insurance, which protects creative professionals from legal challenges to their intellectual property. "We all feel like the system has failed us," Keller says. "There are a lot of aggressive lawyers filing lawsuits and going ham on people." (He's particularly critical of publishers whose rosters are heavier on older catalogs than new acts: "Heritage publishers who aren't making a lot of money are coming out of the woodwork and saying, âWe're going to take a piece of your contemporary hit....'â") Artists are understandably reluctant to publicly disclose that they have copyright insurance, which could open them up to an increase in lawsuits. But music attorney Bob Celestin, who's helped represent acts like Pusha T and Missy Elliott, says it is safe to assume that the majority of artists who show up in Top 10 chart positions are covered in this way...

The popularity of cheap music-production software, which offers the same features to every user, has added another layer of risk. "Music is now more similar than it is different, for the first time," says Ross Golan, a producer and songwriter who has released songs with stars like Ariana Grande and Justin Bieber. "People are using the same sample packs, the same plug-ins, because it's efficient."

Then there's the issue of the finite number of notes, chord progressions, and melodies available...

Apple on Wednesday said that its services business, which includes software for things like news, gaming, apps, music and video, had its best ever year in 2019. From a report: "2019 was the biggest year for Services in Apple's history. We introduced several exciting new experiences for our customers, all while setting the standard for user privacy and security," said Eddy Cue, Apple's senior vice president of Internet Software and Services in a statement. In an effort to showcase its growth to investors, Apple released a slew of engagement numbers for several of its services products. It says: Apple News has over 100 million monthly active users in the U.S., U.K., Australia and Canada. Apple Music now offers over 60 million songs in 115 countries. Apple Podcasts offers over 800,000 shows in 155 countries. Apple Card and Apple Pay are accepted in more than 150 stadiums, ballparks, arenas and entertainment venues.

Music is an ideal medium for interstellar communication. From a report: Each summer for the past 25 years, tens of thousands of people have flocked to Barcelona, Spain, to witness Sonar, a three-day festival dedicated to electronic music, art, and design. To celebrate Sonar's 25th anniversary in 2018, the festival partnered with the Catalonia Institute for Space Studies and the nonprofit METI International to send a series of interstellar messages to Luyten's star, a red dwarf about 12 light-years from Earth. Although red dwarfs are the most common stellar objects in our galaxy, Luyten's star is remarkable for hosting GJ237b, the closest potentially habitable planet outside of our own solar system. No one knows for sure whether GJ237b hosts life, intelligent or otherwise, but if ET does call the planet home, Sonar wants to rock its socks off. Over the course of several nights in late 2017 and early 2018, a radar system in Tromso, Norway, blasted a custom message from Sonar toward GJ237b. Like any good correspondence, the message began with a greeting: In this case, the first 33 prime numbers repeated on two alternating radio frequencies functioned as a stand-in for "hello."

This was followed by a brief tutorial that the message designers hoped would teach ET to extract the music written by Sonar-affiliated musicians and embedded in the message. [...] The Sonar messages are unique insofar as they are the only interstellar transmissions to use songs designed by musicians specifically for communicating with ET. That the messages include a substantial information content places them firmly in the tradition of messaging extraterrestrial intelligences, or METI, a term coined by the Russian radio astronomer Alexander Zaitsev to differentiate the practice from other modes of interstellar communication. The Search for Extraterrestrial Intelligence, or SETI, is focused on listening for ET signals rather than sending them, and "active SETI" is about creating beacons that lack information but signal to alien intelligences that we exist.