Here's my setup, if you can do it.

I presume you have a multitrack of the music.

Play the music with a rough narrow stereo mix through a PA to a room full of
enthusiastic folks, not too loud in volume. If you have available tracks, place
mics in various positions. (I'd be inclined to use a coinicident pair, matched,
back about 1/3 to 1/2 of the distance to the back wall, aimed in the
traditional X pattern. Record these mics onto open tracks.

At mixdown, mix the music in stereo in a medium narrow soundfield (not full to
the sides, but not mono either.) Pan you coincident or ambient mics hard left
and right, and mix them in.

Be careful pf phase cancellation or comb filtering. The primary sound of the
music should be the mults, but you should hear ambience and crowd noise "around
it".

You could even try judicious "ducking". Put each ambient mic track through a
compressor. Use a stereo mix of the music to trigger the compressor. Set the
attack and release very fast. Then you can get louder ambient noise without
overpowering the music.