Pretty universal items, so I think anything would work. You can go dark and non-melodic type stuff. Or use actual songs. Certainly the Midnight Synd type CDs are great.
Don't know the whole setup, but with an actual hearse - I would consider doing some general background sounds thruout the main area, but have a 'tinny' sounding 50's style car speaker coming from the skelly driver's car radio area. And it could be something more comical or lighter music.
Plenty of MardiGras 'durge' music to try. Slow mellodramtic music that bursts into more joyous marches, etc. Don't know about the coffin, but if the coffin could pop open when the music changes as if the guest of honor, was also celebrating to the upbeat music, etc.
If you have a 5.1 type of system, go full creepy. Dark music, and whispering ghouls bouncing from channel to channel 'around' the hearse.
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