Joseph Haydn's String Quartets, Op. 64, is a set of six string quartets composed in 1790. Along with six earlier quartets published under the opus numbers 54 and 55, they are known as the Tost quartets, after the Hungarian violinist and later merchant Johann Tost who helped Haydn find a publisher for the works. Unlike the earlier quartets, Haydn actually dedicated the Op. 64 set to Tost in gratitude for his efforts.[a][3]
List of Opus 64 quartets
Quartet No. 48 in C major, Op. 64, No. 1, FHE No. 31, Hoboken No. III:65
Allegro moderato
Menuetto: Allegretto ma non troppo
Allegretto scherzando
Finale: Presto
Quartet No. 49 in B minor, Op. 64, No. 2, FHE No. 32, Hoboken No. III:68
^This dedication, which may have been made without authorization by Tost, was later removed from some printings of the quartets, apparently at the request of Haydn.[1][2]