dell'arte, and wanted to name the sonata Pierrot Angry at the Moon. The cellist seems to have invented this, writing: "Pierrot wakes up with a start and shakes off his stupor. He rushes off to sing a serenade to his beloved [the moon] who, despite his supplications, remains unmoved. To comfort himself in his failure he sings a song of liberty." Debussy confirmed in a letter to Durand dated 16 October 1916 that the cellist had visited him the previous night, and seemed to have misunderstood him and the music. Debussy dedicated the sonata, and actually the complete project, to his wife Emma, writing "" (The six sonatas for various instruments are offered to honour Emma-Claude Debussy. Her husband.). He completed only three of the six planned sonatas, a second for viola, flute and harp in October 1915, and the third, a violin sonata, in the winter of 1916/17. Bärenreiter published in 2008 a critical edition of the sonata, edited by Regina Back. She used Debussy's sketches from a private collection for the first time, dealing with the balance of the instruments and attempting to clarify ambiguities in the autograph and the first edition, many of which, unfortunately, remain unresolvable. The cello sonata became a staple of the modern cello repertoire and is commonly regarded as one of the finest masterpieces written for the instrument. Structure and music Debussy structured the sonata in three movements: Prologue: Lent, sostenuto e molto risoluto Sérénade: Modérément animé Finale: Animé, léger et nerveux The final two movements are joined attacca. Instead of using sonata form, Debussy followed the models of eighteenth-century mono-thematic sonatas. He was especially influenced by the music of François Couperin. The piece makes use of modes and whole-tone and pentatonic scales, as is typical of Debussy's style. It also uses many types of extended cello technique, including left-hand pizzicato, spiccato and flautando bowing, false harmonics and portamenti. The piece is considered technically demanding. The work takes about 10 minutes to perform. The first movement, Prologue, is in D minor, common time and marked (in Italian) as slow, sustained and very determined. It opens in the style of a French overture. A second motif is pentatonic. A middle section varies both ideas, and contains a cello cadenza. The movement ends in a "murmur" in D major. The second movement is a serenade in D minor, common time and marked (in French) as