By Tanner Stransky
Updated February 07, 2010 at 07:00 PM EST

British jazz composer, saxophonist, and band leader Sir John Dankworth died Saturday at the age of 82 after months of illness. His wife, jazz singer Dame Cleo Laine, made the announcement just before the end of an anniversary concert at The Stables, the theater they founded together, last night. The news was also shared on the theater’s website. Dankworth performed and composed over the years; scored films such as Darling and Modesty Blaise; the theme of television’s The Avengers; and worked as the musical director for many of jazz’s greatest musicians, including Oscar Peterson, Nat “King” Cole, and Ella Fitzgerald.