To play a new song when you start a level:
Put a Trigger Zone over the Player Start Marker. Then have the Main AI Script in the Trigger Zone point to the following script:
Artificial Intelligence Script
;Header
desc = Start Music When Playr In Zone
;Triggers
:state=0,plrwithinzone=1:timerstart,state=1
; Time delay to make sure the global script has finished running
:state=1,timergreater=100:state=2
; Setup the level
:state=2:music=audiobank\music\user\frzover2.wav,musicvolume=100,soundscale=25,state=3
It works for me.
(Not my script. Sorry, I don't remember who I got it from.)