He received a diploma in Jazz Studies (trumpet) from Humber College, and degrees in performance and composition from the University of Alberta.

He has written music for solo instruments, orchestra, chorus, brass quintet, wind ensemble, big band, film, television and theatre.

Dreaming of the Masters I (2003), a jazz concerto written for clarinet soloist James Campbell, is perhaps his most popular work, and received its American premiere by the Boston Pops in 2004.

His orchestral work On the Shoulders of Giants won first prize at the Winnipeg Symphony Orchestra's Composers Competition in 2002.In 2007, the Alberta-based Arktos Recordings Limited label released Collaborations, a CD devoted exclusively to Gilliland's music.

The track listing is: Gilliland is currently Chair of the Music Program and Head of the Composition Department at MacEwan University in Edmonton.