BTW, folks, after downloading this one:

...I noticed that some of the tracks play much quieter than most of my digital music files. I first noticed this particularly with tracks 55-78 which are The Nutcracker by Bonn Classical Philharmonic and Heribert Beissel. When I first downloaded this, I really had to turn the volume up on those tracks compared with most other music I have.
I use foobar2000 as my desktop player. I always knew it had extensive Replay Gain features, but I never really felt the need to experiment with those features. However, I took the time to apply Replay Gain data to this entire Tchaikovsky collection. It really made a nice difference for me and corrected the wide variance between the levels on different tracks in this collection. Here's some further reading if anyone's confused about what I'm talking about:
http://www.bobulous.org.uk/misc/Replay-Gain.html