Ever since Mozart encountered the clarinet in Mannheim in 1778 he loved the instrument's warm and expressive tone. His friendship with Anton Stadler, the clarinetist in the Royal-Imperial Court Orchestra in Vienna, prompted him to compose not only the Clarinet Concerto (K. 622) but also the Quintet of Quintets, which was written two years before his death. Like almost all his works for the clarinet, this Quintet was probably intended originally for the basset clarinet. However, it survives only in two posthumous prints, both of which call for a standard clarinet. These prints form the basis of our edition. As an added bonus, the appendix contains a fragmentary Allegro in B-flat major for the same combination of instruments.