I'm going to be a performance major in the fall.
From my understanding, a lot of schools don't really have just a "music" major. There's degrees in performance, music ed, jazz studies, composition, etc., but I don't think many places offer degrees in just "music".
I think a lot of people just say they're a "music major", when their degree is actually more specific...I'll probably just tell non-music people that I'm a music major, because I think it would sound kind of annoying to say, 'oh, im a SAXOPHONE PERFORMANCE major'.
This is probably the case at most places with developed music programs...the degrees are more individualized, not just "music".
Also, I'm saying this as a classical player...I will be studying classical saxophone. If you're looking to play jazz, you might look at "jazz studies", not necessarily performance.
This is just kind of what I've gathered from my college search. I may be wrong, and this surely doesn't apply to every school or every student.