my girlfriend is a pianist who likes to write her own songs (nothing too serious but she's on garageband alot) while i absolutely zero musical talent whatsoever.

when the topic of music comes up, it gets abit awkward sometimes, and i feel i am not able to 'keep up' with her. to me, i enjoy music or i don't, i identify with a song or i don't, but to her, there are so many more things about music that i find it difficult to grasp.

music is a big part of her (and me, though in a different sense) so i am feeling a tad uncomfortable about this.

has anyone had any experience dating a musician?

Can't say I have any experience in that, musicians irritate me.
But is it really that awkward? I wouldn't expect anyone I dated to be able to keep up everything I knew about.

Stop worrying about it. It is her passion. I am sure there are things you like that she cannot grasp. Learn from her, have her try to teach you stuff and vice versa. It is a good way to bond and she will feel special that you are trying to learn about something she likes.