This thing is really impressive. Never thought I'd see music visualizations (which seem to have gone the way of the dodo) running at 144Hz on my Linux box. I remember the first versions of this, you've made a lot of progress! Your visualizations are really interesting to look at, and they don't have the aliasing artifacts that most visualizations of the time had, I like it.
One thing that doesn't seem to work correctly is importing a whole album: The songs are added out of order, even if the file names sort in the correct order, and the tags are present.