Dennis was a prolific composer in many, many styles. His sense of humor is often self evident.
He composed Gamelan music, a woodwind quintet, vocal and instrumental music in many styles and genres and music for the Fyre and Lightning Consort. He also arranged lots of music, especially Celtic tunes. His culminating work, "A Perfect Day", was composed first as an "Operina for chorus and a woodwind ensemble with soloists and keyboard and then as a "Cantata" for the Fyre and Lightning Consort and guests.