Although this work is listed as a cello sonata by Gérard, it is clearly written for a viola, and it would be better to change the title to: Viola Sonata, G. 18, C minor. According to Gérard (Catalogue of the Works of Boccherini, Oxford 1969, 23-24), Pina Carmirelli, who edited the piece, affirms that it was written for the viola. The alto clef is used by Boccherini sometimes also in works for the cello (to indicate the use of thumb-position), but there are no complete compositions for the cello written in the alto clef.
