Yesterday I came back from work, put myself in front of the PC, and put on some music. I didn’t hear anything.
Tracking down the problem proved to be challenging. It wasn’t just a Rhythmbox problem, because Totem didn’t play anything either. Alsa was up and running. The volume wasn’t muted. I had played a music CD before, so I was thinking along the lines of a blocked audio output, but rebooting the PC didn’t do anything either. This was frustrating.
Then I noticed that my speakers weren’t switched on. Ghaa.
The sad thing is, this has happened to be before. I just don’t learn.