Op. 21
# Op. 21

In music, Op. 21 stands for Opus number 21. Compositions that are assigned this number include:

* Barber – Capricorn Concerto
* Beethoven – Symphony No. 1
* Britten – Diversions for Piano Left Hand and Orchestra
* Chopin – Piano Concerto No. 2
* Dvořák – Piano Trio No. 1
* Enescu – Symphony No. 3
* Giraud – Pierrot lunaire
* Graham – Episodes
* Lalo – Symphonie espagnole
* Larionov – Chout
* Oswald – Cello Sonata No. 1
* Ries – Cello Sonata No. 3
* Sarasate – Spanish Dances, Book I
* Schumann – Novelletten
* Villiers – Elegiac Ode
* Weill – Der Zar lässt sich photographieren
