[1] Speyer became an extra oboist for the Orchestre Colonne, which accompanied the Ballets Russes in France, and in that way participated in several premieres of works by Ravel and Stravinsky.
In early 1913 he joined the newly formed Orchestre du Théâtre des Champs-Élysées, conducted by Pierre Monteux, which gave its first performance on 2 April 1913.
Two months later, he played in this orchestra in one of the most famous concerts of all time: the program included Les Sylphides, Le Spectre de la Rose and the Polovtsian Dances, but is remembered for the raucous premiere of Stravinsky's Rite of Spring.
[2] Speyer came to America in the summer of 1918 with a French military band for a three-week good-will tour, but stayed, as he had been invited to join the Boston Symphony Orchestra, for which he was hired by Henri Rabaud.
Inspired by Speyer's playing, the art patron Elizabeth Sprague Coolidge convinced Arthur Honegger in 1947 to write a concerto for English horn.