The best No 1 records: George McCrae – Rock Your Baby

George McCrae didn't set out to be disco's John the Baptist. He was a 30-year-old session singer on the verge of returning to college to study law enforcement when KC and the Sunshine Band founders Richard Finch and Harry Wayne Casey approached him with a song that was out of their vocal range. It was the product of careful research in the clubs of Miami, where the songwriters observed soul music evolving into something more supple and insistent and learned the tricks of dancefloor success. They got it right to the tune of more than 10m sales. Within a few years disco would be the heartbeat of pop, but in 1974 McCrae was a pioneer. In a chart dominated by glam-rock peacocks he was just some guy with a good voice, lost in music.

See every No 1 hit from 1974