It's hard to master an instrument without being able to read music.

But what do the Beatles, the Who, Eric Clapton, Bob Dylan, Jimi Hendrix, and Van Halen have in common? All are unable to read music. McCartney claimed that he was afraid that learning would adversely affect his ability to create melodies. He wrote a symphony some time ago, but he used a computer program that would translate his music to notes on a page, and he also had help from classical musicians.

Elton John, who was classically trained, learned to read music, but said that he has forgotten how to read music as it wasn't used in his process of song writing.

I also remember hearing that Irving Berlin couldn't read music, and could compose using only the black keys on the piano. He would have been a good piano partner for olivant.