I have this "problem" with KI1 and KI2 on Mame64 (0.183). It starts with a bong sound, but without any music. To solve this you can go to the service menu and return to the game or press + (volume up) and space.
I want to know if this is a bug, mame emulation quirk, or does the original hardware also have this? Is there a solution?
Killer Instinct is an awesome game, with amazing music. The game runs fine, but the Intro is pure nostalgia and hype.