On January 29, 2011 Westman created the lead role of Sandy Keith In the world premiere of Bramwell Tovey's The Inventor.
In 2017 he played Sir John A.
MacDonald in Harry Somers's Louis Riel for the Canadian Opera Company's tribute to Canada's 150th celebrations.
As a recitalist, he has performed for the Marilyn Horne Foundation, Aldeburgh Connection, Aldeburgh Festival, Musikverein, Wigmore Hall, Queen Elizabeth Hall, Morgan Library & Museum, Koerner Hall, Carnegie Hall, Saito Kinen Festival in Japan, Stratford Summer Music, British Broadcasting Corporation, and the Canadian Broadcasting Corporation.
Westman first came to attention at the age of twelve when he was the first boy soprano to perform and record Mahler 4th Symphony with Benjamin Zander and the Boston Philharmonic Orchestra in 1984.
Westman is regularly featured as the Anthem singer for the Toronto Maple Leafs and numerous other NHL franchises.
Four of Westman's recordings have been nominated for a Juno Award.