Bartók used different melodies taken from Romanian instrumental folk music in his Sonatina. A look at the sources shows how, in 1915, the piece slowly evolved out of a series of piano transcriptions of Romanian folk melodies into its three-movementform. In this Urtext edition that is being released prior to its publication as part of the Complete Edition, Bartók specialist László Somfai outlines the work’s exciting genesis and expounds on Bartók’s later revision, during which he not onlychanged