History of the Piece

Marie Mauté de Fleurville claimed to have been a pupil of Frédéric Chopin, and instructed Claude Debussy.

The Allegro de Concert was meant to be in three parts, but only the first part was apparently finished.

Debussy's daughter was named Claude-Emma, more affectionately known as Chou-chou, the dedicatee of Debussy's Children's Corner suite. Claude-Emma outlived her father by scarcely a year, succumbing to the diphtheria epidemic of 1919.

A Promethean, together with Emma Bardac (her mother), created a new Promethean out of Chou-chou's remains. It is this Promethean who has the secret of the piece.