[1] He was a founding member, lead guitarist, pianist, and singer with the Scottish band Marmalade and co-wrote and produced some of their biggest successes, including "Reflections of My Life", "I See the Rain" and "Rainbow".

In 1998 Campbell and co-writer Dean Ford (Thomas McAleese) were awarded a Special Citation of Achievement by the BMI for attaining radio broadcast performances in excess of one million in the US alone.

His paternal grandfather Alfredo Cancellari was an Italian immigrant born near Lucca, Italy, who changed his surname to Campbell in the early 1900s when he settled in Scotland.

Campbell also composed the music for the 1998 BBC Television adaptation of the Minette Walters murder mystery The Scold's Bridle, starring Miranda Richardson, Bob Peck, Siân Phillips, Douglas Hodge, Trudie Styler, and Beth Winslet.

O'Donnell and Campbell departed the series after becoming embroiled in what proved to be a protracted legal dispute in a claim to recover substantial historic royalties with HIT Entertainment, the new owners.