"Happy Jack" is a song by the British rock band The Who. It was released as a single in December 1966 in the UK, peaking at No. 3 in the charts. It peaked at No. 1 in Canada. It was also their first top 40 hit in the United States, where it was released in March 1967 and peaked at No. 24. It was included on the American version of their second album, Happy Jack, originally titled A Quick One in the UK.

The song features Roger Daltrey on lead vocals with John Entwistle singing the first verse, making it one of the few songs composed by Pete Townshend to feature Entwistle on lead vocals. Author Mike Segretto describes Daltrey's vocal as "imitating Burl Ives." 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.Rolling Stone critic Dave Marsh calls this line "the hippest thing" about the song.

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. According to Marsh, "the lyric is basically a fairy tale, not surprisingly, given the links to Pete's childhood.

Greg Littmann interprets the song as a possible reaction to alienation, as Jack allows "the cruelty of other people slide off his back."

Despite its chart success, Who biographer Greg Atkins describes the song as being the band's weakest single to that point. Daltrey reportedly thought the song sounded like a "German oompah song." But Chris Charlesworth praised the "high harmonies, quirky subject matter" and "fat bass and drums that suspend belief. Charlesworth particularly praised Moon's drumming for carrying not just the beat, but also the melody itself, in what he calls "startlingly original fashion." Marsh states that although the song contained little that the band had not done before, it did "what the band did well," giving the "soaring harmonies, enormously fat bass notes, thunderous drumming" and the guitar riffs as examples.

...
Wikipedia