Hey
To start music, either choose it in the trigger or in the init field type playmusic "track1" or whatever. To end it, do what I do, just fade the music out using 5 fademusic 0 . Five being the time it takes to fade out, zero being the volume (0-1 one being the loudest).
Then when you goto start a new peice of music, choose the music or type playmusic "track2" and the type 0 fademusic 1.
eg:
To fadeout:
5 fademusic 0
To start a new track:
Playmusic "track2"; 0 fademusic 1
(O'Neil