Musician jokes

[Lacquer Head]

Cheesy or not, post your best. Let's try to keep them as nerdy as possible

This one will take a bit of music theory to understand, but it's a golden oldie.

A bluegrass guitarist wants to improve his playing and decides to go to the academy of music and become a serious musician. But first he has to pass a little test in musical theory. The teacher asks him:

"What is the subdominant of "C"?" The bluegrass-guitarist doesn't come up with an answer, so the teacher says "Could it be, you don't know what a subdominant is?" "Of course I know that!", he says. "So what's the problem?"
"I always thought, that "C" IS the subdominant!"

SPOILER!!:

A common (but some what accurate) joke is that a large majority of bluegrass songs are played in the key of G. C is the subdominant of G.