2 Le Double is an orchestral work completed in 1959, commissioned by the Koussevitzky Music Foundation for the 75th anniversary of the Boston Symphony Orchestra.

It is written for an orchestra and a second group comprising an oboe, a clarinet, a bassoon, a trumpet, a trombone, two violins, a viola, a cello, a harpsichord, a celesta, and timpani.

[1] The work consists of back-and-forth interaction between the two instrumental groups, like that of a concerto grosso although the approach is different: in this piece, the smaller ensemble acts as a mirror or ghost of the larger one, sometimes playing similar or complementary lines, sometimes contrasting ones.

This arrangement can hardly help evoking the traditional concerto grosso, although my ideal in fact has been to escape from this form whose pre-fabricated dimension seems incompatible with contemporary language.

This mass does not merely confront and dialogue with the larger formation, but at times fuses with, or superimposes itself upon the latter, leaving ample opportunity for polyrhythmics and polytonality.