Hmmm, unfortunately, I don't see a way of having a different vocabulary for different schedules. Indeed, there is only one vocabulary per installation.
That being said, the vocabulary is stored as an option within the WordPress wp_options table and there are filters available for when one retrieves an option. So, there might be a possibility there. The problem is that there's not a consistent way of determining just what the visitor might be looking at. Additionally, there are cases where we're displaying “sessions” from multiple schedules on the same page.
I think that if it became an absolute must have, I would approach it by adding a custom field to the speakers and to the sessions that allows you to indicate if a speaker is a “speaker” or an “artists”, and if the session is a “session” or a “show”.
All that being said, there are actually very few places on the front end where the vocabulary gets used. It's mostly in the back end.
As for the MP3s, it's a bit of a straggle-over from an early implementation of the code and it requires another plugin. The MP3 player that it uses is called FlamPlayer. To see it in action, you can visit http://folkontherocks.com/memo….._year=2010 and click on any of the artist names there. If you're interested, please send me a message to support_at_topquark_dot_com and I'll send you the FlamPlayer plugin. Once that's installed, you can upload MP3s to an artist as you would upload a picture, and the FlamPlayer will get embedded onto their page.