On this date in 1966, The Who released their 7th single in the UK, where it quickly rose to #3 on the charts. Yet another smash hit in their home country. In March 1967, Happy Jack was issued in the United States, becoming their first American single to receive substantial airplay. According to Billboard, it peaked at #24, reaching #13 on Cashbox, and on WABC in New York, which I listened to, managed to briefly enter the Top 10.
In Live At Leeds, Pete Townshend mentioned that it was also the band's biggest hit in Germany, speculating it was because of the oompah rhythm.
To me, what has always stood out about Happy Jack, is Keith Moon's drumming. It's the first, and maybe the only, hit single with the drum as the lead instrument. Also featured is John Entwhistle's fat bass.