Waltz in Ab, no. 15 from Op. 39
Sixteen Waltzes, Op. 39 is a set of waltzes for piano four hands, written by Johannes Brahms. They were composed in 1865, and published two years later, dedicated to Eduard Hanslick. These waltzes were also arranged for piano solo by the composer, in two different versions – difficult and simplified. The three versions were published at the same time, and sold well, contrary to the composer's expectations. In the solo versions, some of the keys were altered from the original duet version (the last four in the difficult version and no. 6 in the easy version).