Cowan entered the music business in the mid-1960s as a member of The Merricoles, a vocal group who won a local talent contest.
Cowan then took up a job as Sales & Marketing manager at Byron Lee's Dynamic Studios, which gave him the experience needed to move into record production, working with artists including Jacob Miller and Inner Circle, Earl Zero, Ray I, Leroy Smart, Ras Michael, The Cimarons, Dean Stone, and Junior Tucker.
Cowan also worked as a Master of Ceremonies at Reggae Sunsplash festivals and at the One Love Peace Concert, organised by Bob Marley.
Back in Jamaica, Cowan with then wife Valerie Chang-Cowan built up his Talent Corporation company, which he had founded in 1975,[4] with artists such as John Holt, Dobby Dobson, Ruddy Thomas, Toots Hibbert, Ernie Smith, Scotty, Jack Radics, and Cowan's second wife Carlene Davis.
[1] In 1982, he released an album, The King's Music, credited to Tommy Cowan & Thunder, and featuring musicians such as Willie Lindo, Robbie Lyn, Lloyd Parks, Bongo Herman, and Dean Fraser, with backing vocals from his wife Carlene Davis, and Beres Hammond.