McKeown was born in the Simpson Memorial Maternity Hospital, Edinburgh, Scotland. He joined the Bay City Rollers in late 1973. The group's intense popularity, nicknamed "Rollermania", took off shortly afterwards. He was with the band until 1978, at which time he left to pursue a career as a solo artist. He released a series of solo albums which saw modest success, primarily in Germany and Japan. In 1988 and 1989 McKeown worked with Dieter Bohlen. The result of their partnership was the album It's A Game. In 1990, he participated in the UK heats of the Eurovision Song Contest with the song "Ball and Chain", which placed fifth.