So I'm sorting through all of my college application stuff right now, and I came through a temporary roadblock.

I received a letter of recommendation from someone whom I asked to write me one, except he wrote it, expecting that I would go for Music Composition (believe it or not); however, I am going for Music Performance. Should I still use this letter of recommendation to send to a university to which I plan to go? (I'm probably going to receive two more letters in the upcoming weeks, but should I still consider using this letter?)

Thanks for any help.

I'd get in contact with the person who wrote you the letter, explain your true intentions in college, and ask he/she to revise the letter.

You want every advantage you can get when it comes to this sort of thing. A misleading letter could potentially set you back. I agree with asking for a revision (I'm sure he would understand).