I was doing some work and listening to music. The music was coming from the desktop that sits in my entertainment center, connected to my TV via hdmi. I'm no audiophile and my tv's audio is good enough for me. It was playing an Audioslave album in Google Music.
In the middle of a song the audio just cuts out. Total silence.
I kick over to a regular tv channel and it is fine. So the tv works.
I check the volume control and nothing is muted. Then I start digging around and there are a crazy number of places that have audio options/hardware settings. I was thinking, "Man I wish this was KDE - so much easier." I finally tracked it down. I'm not sure what happened - maybe an update to a driver for the audio stuff? There's a new audio manager program and I have no idea what started it or why it decided to change my default audio device, but it did. The machine had been up and running for quite a while. And the easy to find interface wouldn't let me switch the default. I had to find another menu via the control panel.