I found a sound tool that’s interesting. I built the SVN version, and while following the Install From Source page I ran into two problems: my ffmpeg wasn’t compiled with –enable-libmp3lame, which apparently resulted in 0-byte output, and I didn’t realize the ‘where ffmpeg’ part of the link was meant for me to fill in, although in retrospect I feel silly. If people are interested in a more in-depth tale I can put together a guide for getting it running under Debian/Ubuntu.
I also discovered via Reddit an interesting logic game called Manufactoria. My sense is that it takes a rather strange type of individual to enjoy it. My complaint is that the music is quiet and the mute button doesn’t actually stop it.