The debut album from The Who, 'My Generation,' was released in 1965 and included this track, which was later released as a single. The song was written by Townshend as a tribute to the Mod Movement in England, specifically targeting the rebellious British youth. The song is still a radio favorite, and has been covered by many modern rock bands, including Pearl Jam and Green Day.

Happy Jack was the first single to make the top 40 in America and was a top 5 UK hit. The song is rare, in that bass player John Entwistle joins Daltrey on the lead vocals for the song. Townshend