"Happy Jack" is a rock song from British rock band, The Who, released in December 1966 in the UK and peaking at number 3. It was also their first top forty hit in the United States, where it was released in March 1967 and peaked at #24. It was included on the American version of their second album, Happy Jack, originally titled A Quick One in the UK. This song features Roger Daltrey on lead vocals with John Entwistle singing the first verse, making it one of the only songs composed by Pete Townshend to feature John Entwistle on lead vocals. At the tail end of "Happy Jack", Townshend can be heard shouting "I saw you!", and it is said that he was noticing drummer Keith Moon trying to join in surreptitiously to add his voice to the recording, something the rest of the band disliked. According to some sources, Townshend reported the song is about a man who slept on the beach near where Townshend vacationed as a child. Children on the beach would laugh at the man and once buried him in the sand. However, the man never seemed to mind and only smiled in response.