He starred in many shows in London's West End, including Evita, March of the Falsettos, The Phantom of the Opera, Les Misérables, and Children of Eden.
He gave several concerts for the organisation and recorded the song "I'll Make My Promises" for the soundtrack album for the Gowans/Larsson musical The Blood of the Lamb, released in 1981.
As a composer Smith wrote scores for several musicals, including King, The Rainbow Girl, That Golden Fortune, Mountains of Peru, Mezzaluna and La Tosca.
A year after his death, A Handful of Keys, a gala tribute concert was held in his honour at the Prince Edward Theatre, London.
The concert featured Michael Ball, John Barrowman, Tracie Bennett, Dora Bryan, Ruthie Henshall, Sally Ann Howes, Millicent Martin, Jane Rossington, Lily Savage, Marti Webb and many other of his co-stars.