Callum trained at Rose Bruford College of Theatre and Performance, Stephen F Austin State University, Texas and Goldsmith’s University of London. He has been making theatre as an actor, writer and musician for over a decade in a variety of genres including musical theatre, live/performance art, immersive theatre, site specific theatre, folk/story-telling, classical texts, film and television.

Callum was a long-time member of Bob Carlton's award-winning ensemble of actor-musicians where he performed in countless productions including Godspell, The Great Gatsby, As You Like It, Treasure Island and Return to the Forbidden Planet. Since then Callum has performed in UK No1 tours, at fringe festivals, in films and and commercials and regularly records audiobooks as a narrator.

Callum is also a writer and, with his writing partner David Shopland, has seen multiple musicals produced professionally since 2009 in a variety of venues in London, Texas, Aberdeen, Bristol and even the National Theatre of China. Shopland and Hughes' musical Living Out Loud was live-streamed to over 250,000 people in 2018. They have also written pop songs for former Only Men Aloud star Ross Leadbeater and were comissioned to write the official anthem for the 2017 BRICS conference.

Callum has also composed the music for more than 10 different productions including Cinderella, The Little Mermaid, The Fir Tree, Into Thin Air, Slasher, Drive Your Road and Furious: The Ballad of '72 to name a few.