Of increasing difficulty, these pieces require an advanced knowledge of the instrument, its technique and of the use of pedals.
The book is divided in the following pieces: 
I. Prélude sur les grands jeux - Allegro 
II. Nazard - Moderato 
III. Contrepoint sur des jeux d’anche – Espressivo 
IV. Française - Allegro 
V. Choral sur la voix humaine - Andantino 
VI. Arabesque sur les flutes - Vivace 
VII. Méditation sur les jeux de fonds - Largo 
VIII. Trio - Moderato 
IX. Voix céleste – Vivo/Lento 
X. Final Rhapsodique - Vivo 
Jean Langlais was a French composer who contributed greatly to the Organ repertoire.