Born in Hobart, Lyall began studying piano and violin from an early age. He graduated from the Tasmanian Conservatorium of Music in 1974 having majored in Performance and Education. The following year he received his first appointment, to Wynyard High School, where he worked for three years. After a two year break, during which time he worked as the Music Projects Officer for the Tasmanian Arts Advisory Board, he returned to teaching in the south of the state. He is currently the woodwind specialist at Warrane and Howrah Primary Schools and Clarence High.

Active in the local music scene over many years, he has played in cabaret, jazz and rock bands and worked for several years as a recording engineer. As a composer, he has written music for use in schools and a large body of work for Australian and American film and television.

In addition to his role with the Derwent Valley Concert Band, Lyall is an augmenting player with the Hobart Wind Symphony.