He was educated at Aberdeen Grammar School, and won a scholarship to the Royal College of Music in London, where he studied viola with Frederick Riddle and compositions with Herbert Howells.
[2] With a Sir James Caird travelling scholarship, he lived for two years in Italy, where he studied composition with Goffredo Petrassi, and played viola in a chamber orchestra.
[3] He was much involved with the BBC Scottish Symphony Orchestra, programming concerts, selecting solosts and arranging visits.
[2] With John Purser, Dalby worked on a 30-part radio series Scotland's Music, which won a Sony Gold Award.
[3] Compositions include a Viola Concerto, performed at the Proms in 1974 with soloist Frederick Riddle;[1] The Mary Bean, written for the Royal Scottish National Orchestra and performed at the Proms; The White Maa, written for the Scottish Chamber Orchestra to celebrate 200 years of Union Street, Aberdeen; and a String Quartet to celebrate 500 years of the University of Aberdeen.