The letter John Lennon wrote to Eric Clapton in 1971 has sold at auction for $35,000.

In the one-page letter, Lennon wrote, "Eric, I know I can bring out something great, in fact greater in you that had been so far evident in your music. I hope to bring out the same kind of greatness in all of us, which I know will happen if/when we get together."

Clapton and Lennon were already friends at that point -- Eric played in the 1969 edition of The Plastic Ono Band. And of course, he also recorded with The Beatles, having played on "While My Guitar Gently Weeps" on The White Album.