Publisher Desc.  Violin, Viola, and Piano. It is very likely that Mozart wrote the solo Viola part in this work for himself, and that he was the soloist in its first performance. In fact, in order to enhance the brilliance of the solo Viola's sound, he wrote its part in D Major, instructing that the instrument be tuned a half-tone high (this is, however, not a feature of the present edition). Edited by Carl Schaefer.