Sérénade in E-flat major, Op. 15

Camille Saint-Saëns' Serenade in E flat major, Op. 15 (French: Sérénade en mi bémol majeur) is a chamber composition for a quartet consisting of piano, organ, violin, viola (or cello) composed in 1865. It is one of the earliest works by the composer making use of an organ (or harmonium) in a chamber ensemble, preceded only by the Six Duos for harmonium and piano, Op. 8. In addition to the original scoring the work has been transcribed for orchestra, piano solo, piano four-hands and for piano quartet, with a cello taking the part of the organ.