Alsa worked fine with XMMS on TCL 1.x, but both Alsa and OSS have fast sound on TCL 2 (so far tried flash, mplayer, and xmms). My machine (Compaq Deskpro EN) is mentioned on some Linux blogs as one that has this problem, so it's not really a TCL thing. I can adjust the playback speed in command-line mplayer to compensate but for whatever reason music still doesn't sound quite right.
I'm using OSS now but may give alsa another try.