The Cello Sonata (Sonate pour violoncelle et piano), L. 135, is a sonata for cello and piano by Claude Debussy. It consists of three movements: Prologue, Sérénade and Finale. It was composed and published in 1915. After performances in London and Geneva in 1916, the sonata's official premiere in Paris was played in 1917 by Joseph Salmon and Debussy. It was the first chamber music work in his late style, and became one of the key works in the repertoire from the 20th century.

This is a list of compositions by Claude Debussy categorized by genre, and sorted within each genre by "L²" number, according to the 2001 revised catalogue by musicologist François Lesure, which is generally in chronological order of composition date. (For convenience, the "L¹" numbers from Lesure's original 1977 catalogue are also shown below. They were widely used on recordings, and so on, for twenty years.) (The "L¹" and "L²" headers can be clicked on to sort the entire list by either numbering. A second click will reverse the order. Reloading the webpage will restore the genre-category order.)

Achille Claude Debussy (French pronunciation: [aʃil klod dəbysi]; 22 August 1862 – 25 March 1918) was a French composer. He is sometimes seen as the first Impressionist composer, although he vigorously rejected the term. He was among the most influential composers of the late 19th and early 20th centuries. Born to a family of modest means and little cultural involvement, Debussy showed enough musical talent to be admitted at the age of ten to France's leading music college, the Conservatoire de Paris. He originally studied the piano, but found his vocation in innovative composition, despite the disapproval of the Conservatoire's conservative professors. He took many years to develop his mature style, and was nearly 40 when he achieved international fame in 1902 with the only opera he completed, Pelléas et Mélisande. Debussy's orchestral works include Prélude à l'après-midi d'un faune (1894), Nocturnes (1897–1899) and Images (1905–1912). His music was to a considerable extent a reaction against Wagner and the German musical tradition. He regarded the classical symphony as obsolete and sought an alternative in his "symphonic sketches", La mer (1903–1905). His piano works include sets of 24 Préludes and 12 Études. Throughout his career he wrote mélodies based on a wide variety of poetry, including his own. He was greatly influenced by the Symbolist poetic movement of the later 19th century. A small number of works, including the early La Damoiselle élue and the late Le Martyre de saint Sébastien have important parts for chorus. In his final years, he focused on chamber music, completing three of six planned sonatas for different combinations of instruments. With early influences including Russian and Far Eastern music and works by Chopin, Debussy developed his own style of harmony and orchestral colouring, derided – and unsuccessfully resisted – by much of the musical establishment of the day. His works have strongly influenced a wide range of composers including Béla Bartók, Igor Stravinsky, George Gershwin, Olivier Messiaen, George Benjamin, and the jazz pianist and composer Bill Evans. Debussy died from cancer at his home in Paris at the age of 55 after a composing career of a little more than 30 years.

La mer, trois esquisses symphoniques pour orchestre (French for The sea, three symphonic sketches for orchestra), or simply La mer (The Sea), L. 109, CD. 111, is an orchestral composition by the French composer Claude Debussy. Composed between 1903 and 1905, the piece premiered in Paris in October 1905. It was initially not well-received; even some who had been strong supporters of Debussy's work were unenthusiastic, even though La mer presented three key aspects of Debussy's aesthetic: Impressionism, Symbolism and Japonism. The work was performed in the US in 1907 and Britain in 1908; after its second performance in Paris in 1908, it quickly became one of Debussy's most admired and frequently performed orchestral works. The first audio recording of the work was made in 1928. Since then, orchestras and conductors from around the world have set it down in many studio or live concert recordings.

The Piano Trio in G major, L. 5 (revised Lesure catalogue; originally L. 3), was written by an 18-year-old Claude Debussy in 1880 in Fiesole, Italy, where he resided at Nadezhda von Meck's. Most of the autograph of the work was thought to be lost until 1982, when it was discovered from the legacy of Maurice Dumesnil, a pupil of Debussy's. The first edition was published in 1986.

The Première rhapsodie (First Rhapsody), L. 116, CD. 124, by Claude Debussy is a piece for accompanied clarinet. Composed between December 1909 and January 1910, it was dedicated to the French clarinet professor Prosper Mimart. In 1909, Gabriel Fauré, Director of the Conservatoire de Paris, named Debussy to its board of directors (le Conseil Supérieur). One of Debussy's first duties was to supply two works for the next year's clarinet examinations. The Rhapsodie was first performed as part of the examinations on July 14, 1910. The original composition was for clarinet and piano; Debussy published his own orchestration of the accompaniment in 1911, after the official premiere with Mimart. In 1901, Debussy had been commissioned to write a work for alto saxophone and orchestra by Elise Hall, but never finished the 1903 draft during his lifetime. This "Second Rhapsody" was later completed by Jean Roger-Ducasse as Rapsodie pour orchestre et saxophone.

Claude Debussy's Six sonatas for various instruments (French: Six sonates pour divers instruments) was a projected cycle of sonatas that was interrupted by the composer's death in 1918, after he had composed only half of the projected sonatas. He left behind his sonatas for cello and piano (1915), flute, viola and harp (1915), and violin and piano (1916–1917).

There is a long tradition in classical music of writing music in sets of pieces that cover all the major and minor keys of the chromatic scale. These sets typically consist of 24 pieces, one for each of the major and minor keys (sets that comprise all the enharmonic variants include 30 pieces). Examples include Johann Sebastian Bach's The Well-Tempered Clavier and Frédéric Chopin's 24 Preludes, Op. 28. Such sets are often organized as preludes and fugues or designated as preludes or études. Some composers have restricted their sets to cover only the 12 major keys or the 12 minor keys; or only the flat keys (Franz Liszt's Transcendental Études) or the sharp keys (Sergei Lyapunov's Op. 11 set). In yet another type, a single piece may progressively modulate through a set of tonalities, as occurs in Ludwig van Beethoven's 2 Preludes through all the Major Keys, Op. 39. The bulk of works of this type have been written for piano solo, but there also exist sets for piano 4-hands; two pianos; organ; guitar; two guitars; flute; recorder; oboe; violin solo; violin and piano; cello solo; cello and piano; voice and piano; and string quartet. There are examples of attempts to write full sets that, for one reason or another, were never completed (Josef Rheinberger's organ sonatas, Dmitri Shostakovich's string quartets, César Franck's L'Organiste).

Syrinx, L. 129, is a piece of music for solo flute which Claude Debussy wrote in 1913. It generally takes three minutes or less to perform. It was the first significant piece for solo flute after the Sonata in A minor composed by C. P. E. Bach over 150 years before (1747), and it is the first such solo composition for the modern Böhm flute, developed in 1847. Syrinx is commonly considered to be an indispensable part of any flutist's repertoire. Many musical historians believe that "Syrinx", which gives the performer generous room for interpretation and emotion, played a pivotal role in the development of solo flute music in the early twentieth century. Some say Syrinx was originally written by Debussy without barlines or breath marks. The flutist Marcel Moyse may have later added these, and most publishers publish Moyse's edition. The piece is commonly performed off stage, as it is thought when Debussy dedicated the piece to the flutist Louis Fleury, it was for him to play during the interval of one of Debussy's ballets. Syrinx was written as part of incidental music to the play Psyché by Gabriel Mourey, and was originally called "Flûte de Pan". It was given its final name in reference to the myth of the amorous pursuit of the nymph Syrinx by the god Pan, in which Pan falls in love with Syrinx. Syrinx, however, does not return the love to Pan; she turns herself into a water reed and hides in the marshes. Pan cuts the reeds to make his pipes, in turn killing his love. Syrinx has also been transposed and performed on the saxophone and other instruments. It quickly became a piece of standard literature for the saxophone, and has been recorded on both the alto and soprano saxophones. It is also a track on Caprice [1] by the trumpeter Alison Balsom [2].

Claude Debussy's Six sonatas for various instruments (French: Six sonates pour divers instruments) was a projected cycle of sonatas that was interrupted by the composer's death in 1918, after he had composed only half of the projected sonatas. He left behind his sonatas for cello and piano (1915), flute, viola and harp (1915), and violin and piano (1916–1917).