In music, Op. 11 stands for Opus number 11. Compositions that are assigned this number include: * Barber – Adagio for Strings * Barber – String Quartet * Beethoven – Piano Trio, Op. 11 * Boccherini – String Quintet in E major, Op. 11, No. 5 * Brahms – Serenade No. 1 * Chopin – Piano Concerto No. 1 * Dvořák – Romance in F minor * Elgar – Sursum corda * Enescu – Romanian Rhapsodies * Fanny Mendelssohn – Piano Trio * Gottschalk – Le Mancenillier * Granados – Goyescas * Grieg – In Autumn * Hindemith – Viola Sonata No. 1 * Hindemith – Violin Sonata No. 2 * Karłowicz – Lithuanian Rhapsody * Mendelssohn – Symphony No. 1 * Prokofiev – Toccata * Racine – Cantique de Jean Racine * Schoenberg – Drei Klavierstücke * Schumann – Piano Sonata No. 1 * Scriabin – 24 Preludes, Op. 11