Guitarist/vocalist George and bassist/vocalist Louis formed the band Johnson Three Plus One with older brother Tommy, and their cousin Alex Weir, while attending school in Los Angeles, California. When they became professionals, the band backed such touring R&B acts as Bobby Womack and the Supremes. George and Louis Johnson later joined Billy Preston's band, and wrote "Music in My Life" and "The Kids and Me" for him before leaving his group in 1973.
Quincy Jones hired them to play on his LP Mellow Madness, and recorded four of their songs, including "Is It Love That We're Missing?" and "Just a Taste of Me".
After touring with various artists like Bobby Womack and Billy Preston, Quincy Jones hired them for a tour in Japan and produced their debut album "Look Out For", released in March 1976. Their "Right On Time" album was released in May 1977 and reached number 13 on the Billboard Hot 200. Blam!! came out in August 1978 and reached number 7 on the Billboard 200.
Two of the duo's songs were featured on the soundtrack of the 1976 film Mother, Jugs & Speed. The instrumental track Thunder Thumbs and Lightnin' Licks refers to the brothers' nicknames. "Get the Funk Out Ma Face" was cowritten with Quincy Jones.
Among their most popular songs are I'll Be Good to You (Billboard Hot 100 #3 in 1976), Strawberry Letter 23 (Hot 100 #5 in 1977), Ain't We Funkin' Now (1978), and Stomp! (Hot 100 #7 and Hot Dance Music/Club Play #1 in 1980). Their styles include funk, disco, and R&B ballads.