>A musical performance is copyrightable
A recording of a musical performance is copyrightable. But I believe the copyright would belong to whoever made the recording, not the performing musicians (assuming the work being performed is public domain, like Beethoven)
> Choreography instructions are also likely uncopyrightable, but the performances of one would be.
As far as I know, this is almost exactly wrong. Choreography instructions may be copyrightable. A performance of a dance is not subject to copyright, but a video recording of that performance may be.
> To qualify for registration, a choreographic work or pantomime must be fixed in a tangible medium of expression [1]