[4] In the summer of 1938 William Walton asked Brosa to look over and suggest improvements for the first two movements of his Violin Concerto, which he was writing for Jascha Heifetz.
Britten played his Suite for Violin and Piano with Brosa at the International Society for Contemporary Music Festival held in Barcelona in 1936.
Brosa gave the first performance of the concerto at Carnegie Hall on 28 March 1940, playing on his Vesuvius Stradivarius of 1727 with the New York Philharmonic, conducted by John Barbirolli.
[8] Brosa was also the soloist for the premieres of Helen Perkin's Spring Rhapsody in 1937,[9] Denis ApIvor's Violin Sonata, Op.
He was also the leader of the Pro Arte Quartet in the US, and in the UK worked in partnership with pianist and teacher Kathleen Long between 1948 and 1966.