For many years he was one of the panel engaged by the BBC to read new scores to help assess whether the works should be performed and broadcast.

[9] His compositional output was varied and large and included five symphonies, four operas, several concertos, film scores and string quartets.

His classic film scores included Green for Danger (1944), Odd Man Out (1947), Desert Victory (1943), Fires Were Started (1943), The History of Mr. Polly (1949), The Fallen Idol (1948), The Black Tent (1956), The Way Ahead (1944), The True Glory (1945) and The Crimson Pirate (1952).

Some works, for which only fragmentary sketches remained, were reconstructed by Philip Lane or Christopher Palmer from the film soundtracks themselves.

[12] Alwyn's concerto for harp and string orchestra, Lyra Angelica, was popularized when the American figure skater Michelle Kwan performed to it at the 1998 Winter Olympics.

[13] Alwyn spent the last 25 years of his life at Lark Rise, Dunwich Road, Blythburgh, Suffolk, where he composed his Concerto Grosso no.