Music.tbl (*-mus.tbm) is now XMT-compliant.

Basically, in order to specify individual soundtrack fields, you just do this:
$Normal 1:
$Normal 2:
$Normal 3:
$Ally Arrival 1:
$Ally Arrival 2:
$Enemy Arrival 1:
$Enemy Arrival 2:
$Battle 1:
$Battle 2:
$Battle 3:
$Failure 1:
$Victory 1:
$Victory 2:
$Dead 1:
At this point I consider the feature experimental, because I'm not quite happy with how messy it makes music.tbl. It would be possible to just use the four-letter names for the track (eg "NRML_1, NRML_2, NRML_3, AARV_1, AARV_2, EARV_1, EARV_2, BBTL_1, BTTL_2, BTTL_3, FAIL_1, VICT_1, VICT_2, DEAD_1) if people would prefer it.
Note that this is different from the order using the "Name:" method. I figured that with named fields like this, it would probably be better to group music in a more sensible order.
Build (with sample mVP 3.6.8 TBL):
http://fs2source.warpcore.org/exes/latest/C13122005.zip