'Six Pieces' Op. 19 is the first collection of piano pieces by Tchaikovsky which contributed significantly to his growing renown as most important Russian composer apart from Anton Rubinstein. Famous contemporary pianists like Nikolai Rubinstein and Hans von Bülow performed Rêverie du soir (Op. 19, No. 1) or Thème original et variations (No. 6) in their concerts in the 1870s. Commissioned by his Moscow publisher P. I. Jurgenson, Six Pieces Op. 19 was composed by Tchaikovsky in the summer and autumn of 1873, i.e. during his time as professor of theory at the Moscow Conservatoire.Bülow had entered 'little changes' in his own copy of the first edition of Variations Op. 19/6. There is, however, no documentary proof which of Bülow's changes Tchaikovsky eventually included in the Nouvelle édition revue et corrigée par l’auteur of Op. 19 published only in 1890. The present new edition therefore contains both versions of the Variations. Tchaikovsky's version of the first edition can be found in the appendix of the present volume, Bülow's version expressly adopted by Tchaikovsky is presented together with Nos. 1-5 in the main text of the volume on the basis of the Nouvelle édition revue et corrigée par l’auteur from 1890.