Donovan Leitch gave Mick Jagger 'Ruby Tuesday' in exchange for Mick's collaboration on 'Sunshine Superman.' Mick was at a party (about learly 1966) where Donovan was playing some new songs to some girls who had gathered around him. One of these songs was an early version of SS called 'Sunshine Came Softly,' a quiet song in his early accoustic style. Mick suggested that if Donovan wanted to hit it big, he'd have to give his music more edge, and offered to work with him on the song. Mick's contibution can be recognized in the harder style and in lyrics like, 'Mm mm-mm-mm, Any trick in the book now babey that I can find...' In exchange for this, Donovan gave Mick an unfinished song, 'Ruby Tuesday. ' (The Stones later added the final verse.) They traded a couple of other songs, and agreed that the exchange included song writing credits.