For well over two decades, researchers have sought to build music listening software that can address the deluge of music growing faster than our Spotify-spoilt appetites.
... One particular area of intense research has been devoted to getting these “computer ears” to recognise generic attributes of music: genres such as blues or disco, moods such as sad or happy, or rhythms like waltz or cha cha. ... So far, we see some systems achieve accuracies that equal that of humans. The appearance of this human-level performance, however, may instead be a classic sign of unintentional cues from the experimentalist — a danger in experimental design recognised for over a century.