He became a founding member of The Skatalites as well as playing in various bands such as The Sheiks, The Soul Brothers, The Soul Vendors and Sound Dimension. Among Mittoo’s contributions in the mid to late 1960′s were “Darker Shade of Black” (the basis for Frankie Paul’s “Pass the Tu Sheng Peng”), Freddie McGregor’s “Bobby Babylon”, Alton Ellis’ “I’m Still in Love with You”, The Cables’ rocksteady anthem “Baby Why” and Marcia Griffiths’ first hit, “Feel Like Jumping”. He played for Lloyd “Matador” Daley in 1968 and 1969.
He emigrated to Toronto, Canada at the end of the 1960s. There he recorded three albums, Wishbone (Summus), Reggae Magic (CTL) and Let’s Put It All Together (CTL). He also set up the Stine-Jac record label, as well as running a record store.
In 1970, his song “Peanie Wallie” was versioned by The Wailers, becoming the hit “Duppy Conqueror”. He had a hit with Wishbone in 1971. He performed in local Toronto lounges throughout the 1970s. Mittoo assisted Toronto-area reggae musicians, including Earth, Roots and Water, Esso Jaxxon (R. Zee Jackson), Carl Harvey, Lord Tanamo, Boyo Hammond, Carl Otway, The Sattalites, Jackie James and Jason Wilson. Mittoo continued to record for Jamaican producers in the 1970s, mostly Bunny Lee.
In the 1980′s, he worked regularly with Sugar Minott. In 1989, Mittoo joined the reunited Skatalites, but health problems soon forced him to bow out. In 1989 and 1990 he recorded Wild Jockey for Lloyd Barnes’ Wackies label.
Mittoo entered a hospital on December 12, 1990 and died of cancer four days laters on December 16 at the age of 42. His funeral was held at the National Arena in Kingston, Jamaica, on 2 January 1991. Hortense Ellis, Neville ‘Tinga’ Stewart, Desmond “Desi Roots” Young, Ruddy Thomas, Tommy Cowan, Clement “Coxsone” Dodd were among the attendees. A memorial concert was held around the same time, with performances by Vin Gordon, Leroy “Horsemouth” Wallace, Glen ‘Bagga’ Fagan, Pablo Black, Robbie Lyn, Michael “Ibo” Cooper, Ken Boothe, Delroy Wilson, Carlene Davis, Tinga Stewart and others.