http://en.wikipedia.org/wiki/Gene_Clark
Gene Clark wrote or co-wrote many of The Byrds' best-known originals, including: "I'll Feel a Whole Lot Better", "Set You Free This Time", "Here Without You", "If You're Gone", "The World Turns All Around Her", "She Don't Care About Time" and "Eight Miles High". He played harmonica for the band, too (notably on "Set You Free This Time"). Bassist Chris Hillman noted years later in various interviews remembering Gene: "People don't give enough credit to Gene Clark. He came up with the most incredible lyrics. I don't think I appreciated Gene Clark as a songwriter until the last two years. He was awesome! He was heads above us! Roger wrote some great songs then, but Gene was coming up with lyrics that were way beyond what he was. He wasn't a well-read man in that sense, but he would come up with these beautiful phrases. A very poetic man--very, very productive. He would write two or three great songs a week". "He was the songwriter. He had the "gift" that none of the rest of us had developed yet.... What deep inner part of his soul conjured up songs like "Set You Free This Time," "I'll Feel A Whole Lot Better," "I'm Feelin' Higher," "Eight Miles High"? So many great songs! We learned a lot of songwriting from him and in the process learned a little bit about ourselves. At one time, he was the power in the Byrds, not McGuinn, not Crosby—it was Gene who would burst through the stage curtain banging on a tambourine, coming on like a young Prince Valiant. A hero, our savior. Few in the audience could take their eyes off this presence."