In actual fact, about 5 months after I was told that I was a saxophonist (at age 13), my band director expressed an interest in a particular piece of music and asked if I might be able to play it.

(It was a Beethoven piece.)

The only dots I could find for the piece was an arrangement for piano in A♭ minor. (signature on the score C♭ major)

When I played it for him, straight from the dots, he affirmed that it sounded fine but complained that it would be a lot of work for him to rewrite the piano part for an accompaniment for my B♭ saxophone.

So I kicked it up two semitones and played it for him in what was B♭ minor (C♯ major) for my instrument, so he'd be able to play from the original score in A♭ minor (C♭ major).

Then he looked at the sheet music and discovered he'd be playing 7 flats (while I played 7 sharps) and decided he wasn't really as interested as he thought he'd been.

I never did bother to look up whether that sheet music really was the key that Beethoven used when he wrote the piece.

John