What was Bob first song?

"Hey Mr. Tambourine Man" was the first single released by the Byrds, a folk-rock band formed in Los Angeles in 1964. The song was written by Bob Dylan and released on their debut album, Mr. Tambourine Man, in 1965. Although it was attributed to Dylan, he only wrote the lyrics, while the melody was composed by Roger McGuinn, David Crosby, Gene Clark, and Chris Hillman, the founding members of the Byrds.