His film and television credits include Disney, Nickelodeon, Viacom, HBO, PBS and Syfy as well as commercials for Dodge, Mattel and General Mills.
After moving to the US permanently in the late 1980s, Fennell co-wrote with David Frank the track "If You Believe" for soul singer Kenny Thomas' 1991 album Voices.
In 2010, Fennell co-wrote "Crash and Burn" and "Black and White" with Alex Smith and Karen Louise Barrow.
"Crash and Burn" achieved high rotation on BBC Radio 2's B-List and the Jason Nevins remix reached number 2 in the Music Week Commercial Pop Club Chart.
In 2013/14, Fennell wrote and co-produced with Jason Silver the album Bring It Back for singer Brenda Edwards.
In the early 2000s, he composed and recorded songs for Bear in the Big Blue House (Disney), Little Bill (CBS), Out of the Box (Nickelodeon), Gullah Gullah Island (Nickelodeon), Cyberchase (PBS), Scrubs (ABC) and Nash Bridges (CBS).