Mozart was without a doubt one of Edvard Grieg’s favourite composers. When his mother gave lessons or entertained family and friends for an evening of music, it was the music of Wolfgang Amadeus Mozart which made the greatest impression on him. During the winter of 1876/77 he arranged four of Mozart’s nineteen piano sonatas for two pianos by adding his own, newlsy composed part. What is special about Grieg’s adaptations of the Mozart sonatas is that he has not reworked them in the traditional – and perhaps derogatory – manner. Grieg’s unusual achievement lies in the fact that he has retained Mozart’s text unchanged, adding an entirely new part which can be performed together with the original. When both parts are played, they interweave and become something entirely new. Two different musical styles meet in dialogue, ending up in a symbiosis of colour and texture. Mozart’s music expands in time and space. Grieg’s additional piano part is a romantic’s respectful embrace, a romantic commentary; Mozart in romantic guise.