The Concerto for Clarinet and Orchestra was written in October 1791, about two months before Mozart's death, and destined for Anton Stadler, the famous clarinettist. The first movement exists in a sketch in G major for Basset Horn and Orchestra composed towards the end of 1789. This edition has been published in two versions: in the original in A for Clarinet in A, and in a transposed version in B-Flat for Clarinet in B-Flat. Available here is the version for Clarinet in B flat , with Piano reduction by Ernest Roth and Clarinet arrangement by Frederick J. Thurston.