Free public domain sheet music from IMSLP / Petrucci Music Library
||Toccata per Clavicembalo o Pianoforte ; Sonata
||piano or harpsichord
||RISM 200230115 (abschrift, as "Sonata VI or Toccata, in Bibliotheca Albertina, Leipzig)
- Originally published as piano Sonata, Op. 11.
- Do we know at least whether the _composer_ called it a toccata or a sonata on any autograph ms that might possibly have survived (rare, in Clementi’s case, I know, with the conflagration carried on by his relatives, but there are some)? That's quite important - Schissel (see RISM link for some information about a manuscript copy)