In music, Op. 64 stands for Opus number 64. Compositions that are assigned this number include:
Britten – A Midsummer Night's Dream Chopin – Minute Waltz, Op. 64, No. 1 Chopin – Waltz in A-flat major, Op. 64, No. 3 Chopin – Waltz in C-sharp minor, Op. 64, No. 2 Dvořák – Dimitrij Grieg – Symphonic Dances Haydn – String Quartets, Op. 64 Mendelssohn – Violin Concerto Prokofiev – Romeo and Juliet Schumann – Romanzen & Balladen volume IV (3 songs) Scriabin – Piano Sonata No. 7 Sibelius – The Bard (), tone poem for orchestra (1913, revised 1913) Tchaikovsky – Symphony No. 5