Conceived as an eightieth-birthday present for the composer’s longstanding friend and supporter Pierre Boulez this colorful and often humorous piece is a swirl of reflections on six notes that spell out the dedicatee’s surname. The score is also a homage to the Ensemble InterContemporain, which was to give the first performance (as also of the composer’s Penthode and his concertos for oboe and clarinet). Accordingly, the music is a sparkling sequence of virtuoso solos and duets, including a comic turn for contrabass clarinet in the extreme low register, bright discourses for flutes and trumpets, and a cello thrust in which, Carter has observed, “the cello plays a wrong note, B natural, which the orchestra doesn’t like, so then it plays the right note, which is B flat.”