Truett Pratt grew up in San Antonio, Texas and sang in his church choir. Jerry McClain also sang in the choir in his hometown of Pasadena, California. McClain formed his first band, American Scene, with Michael Omartian in the mid-1960s. In 1970, Omartian began a successful record producing career, eventually recording hits for Michael Bolton, Christopher Cross, Donna Summer, Rod Stewart, Amy Grant, Gary Chapman, and 4HIM, among others. In the early 1970s he introduced McClain to Pratt. They formed a band called Brother Love, and began recording commercial jingles.

That year, the producers of ABC-TV's successful situation comedy Happy Days decided to replace its theme song, Bill Haley and the Comets' "Rock Around the Clock", with a new song written especially for the show. The tune was written by Norman Gimbel and Charles Fox, who also wrote themes for Love American Style, Wonder Woman, Laverne and Shirley, and The Love Boat. Omartian was chosen to produce the song, and he recommended Pratt & McClain to record it. Multiple short arrangements were produced for the show and its promotional vehicles, and a full-length version was recorded for popular release.

"Happy Days" went to #5 in the Billboard Hot 100 chart in early 1976, and was included on Pratt & McClain's second LP, Pratt & McClain Featuring Happy Days. The single also peaked at #31 in the UK Singles Chart. The follow-up, a cover of Mitch Ryder's "Devil With the Blue Dress On," peaked at US #71 in the summer of 1976.The band never charted again, but their lone top-40 single endures on the Happy Days perpetual syndication run,