A pupil of Gabriel Fauré, Koechlin occupies a position of honour among French composers, highly respected as a teacher and counting among his own pupils Poulenc and Tailleferre, while exercising a strong influence on Milhaud and the younger composers associated with Satie. His pre-eminence as a theorist has led to undue neglect of his music.
Koechlin's compositions include symphonies and symphonic poems, some of the latter inspired by Kipling's Jungle Book, as well as a symphonic poem based on Romain Rolland's Le buisson ardent, a study of composer's block.
Koechlin made a significant addition to French song, with choral and solo settings of texts by contemporaries and earlier writers.
Koechlin's works include a quantity of chamber music for various instruments, notably a flute sonata, a wind septet and a piano quintet, with a series of compositions, Les chants de nectaire, for solo flute..
Much of Koechlin's piano music was written before 1920. There are sets of easy pieces and exercises, five Sonatinas and sets of pieces under the title Esquisses (Sketches) and Paysages et marines (Land- and Sea-scapes).