Symphony No. 2, "Le Double" (1955-59) was commissioned by the Koussevitzky Foundation for the 75th anniversary of the Boston Symphony Orchestra who premiered it on 11th December 1959 under the baton of Charles Munch. It is scored for a 12-strong chamber ensemble featuring representatives from each instrumental family (oboe, clarinet, bassoon, trumpet, trombone, harpsichord, celeste, timpani and string quartet) in addition to a full orchestra.
The formation allows for subtle interplay between the two musical protagonists as they join forces, confront each other and offer reflected images of each other in a series of shifting inter-relationships. It is this dual personality, together with a use of stereophonic effects and polyrhythms which gives the symphony its subtitle "Le Double". As the composer put it, it's a musical play of mirrors and of contrasting colours'.