Without any further reading, I'm assuming each bullet is tuned to play a certain note, and you play the national anthem by firing a bunch of them in sequence

u could get multiple notes in order out of em if they had a tracer base that unblocks more holes while burning off during flight

You could in theory make a channel with a bunch of different stable whistle frequencies, and add some other aerodynamic feature that kicks it through them. I doubt you could reasonably do more than a few notes that way, though, and you probably have to hit them in order.

More likely it's just multiple bullets, as the other reply said.

Yes but because the military industrial complex arm of the government is subsidizing it.

We treat them like they're free

The Army's XM7 can do that, but there's a nuance.

It's false https://bulletin.accurateshooter.com/2011/12/from-italy-with-holes-the-radical-ported-compbullet/