Adagio and Rondo in C minor K.617 (1791)

Adagio – Allegretto

Benjamin Franklin’s glass armonica (as he called it) was apparently of dubious value in chamber music even when there were examples of the instrument to be found and musicians to perform them. The Morning Chronicle’s report on what was almost certainly a performance by the blind virtuoso Marianne Kirchgässner of Mozart’s Adagio and Rondo at a Haydn-Salomon concert in the Hannover Sqare Rooms in March 1794 suggests as much: “Her taste is chastened, and the dulcet notes of the instrument would be delightful indeed, were they more powerful and articulate; but that, we believe, the most perfect execution cannot make them. In a smaller room, and an audience less numerous, the effect must be enchanting. Though the accompaniments were kept very much under, they were still occasionally too loud.” So we shouldn’t be too disappointed that the solo part in the Adagio and Rondo Mozart wrote for Mme Kirchgässner in 1791 will be performed on this occasion, as on most others, on the piano.

It seems unlikely that the first performance, since it was given in a space as large as the Kärntnerthor theatre in Vienna, had been any more successful than the London performance three years later. Clearly, however, the composer had taken the special acoustic qualities of the glass armonica into account. The accompanying ensemble of flute, oboe, viola and cello is a new one for Mozart and is scored in such a way, with the flute taking the lead in partnering the solo instrument, that one can almost imagine even with a piano how the original ensemble sounded. There is a particular poignancy in applying C minor harmonies to such a vulnerable instrumental personality – not least when Die Zauberflöte, on which Mozart was working at the time, comes to mind. The Allegretto Rondo is in C major and, although the armonica (or piano) asserts its solo authority by introducing both main themes, the accompanying quartet treats it not only respectfully but also protectively, assuming thematic responsibility only for the second, charming but relatively unimportant second episode. The whole work is such an exquisite creation that it modifies regret that only six months before his death Mozart should have been devoting his attention to an instrument that was obsolete almost as soon as it was invented.