In 1864, Salzburg’s Mozarteum Foundation secured a collection of musical autographs known as “Nannerl’s Notebook”—long assumed to have been a collection of pieces assembled by Leopold Mozart for his daughter Maria Anna, known in her youth by the nickname “Nannerl.” Among the eighteen works contained in this collection was a 75-bar, five-minute concerto movement for keyboard transcribed in Leopold’s handwriting which had long been assumed to have been his work. Only the solo part exists–the orchestral passages have not been retained. Now, however, musicologists studying the manuscript state that they can establish “with a likelihood bordering on certainty” that the work was composed by Nannerl’s brother, Wolfgang Amadeus, reports Vienna’s Der Standard: (S.H. transl.)
”neither the style of composition nor the speedy, corrected handwriting correspond to Leopold’s authorship,” argues Ulrich Leisinger, a Mozart researcher in the Mozarteum Foundation. “It’s far more likely that Wolfgang Amadeus played this composition for his father on the piano, and that it was then transcribed for the still unpracticed Wolfgang in the notebook, and subsequently corrected.” Father Leopold did not compose piano works of such breakneck virtuosity and extraordinary difficulty (for the period 1763-64)—in it the soloist is required to cross his hands and let them fly wildly over the keyboard, Leisinger stated.
Florian Birsak gave the work its public premiere this weekend, performing in Salzburg on a period fortepiano. Swiss television reported on the developments last night: