
Anton Stadler, for whom Mozart wrote the Clarinet Concerto, experimented with a 'basset clarinet' that extended the instrument's range downwards by a major third.
Mozart completed his only surviving bassoon concerto, K 191 (186e), in Salzburg on June 4, 1774.
Mozart was reluctant to compose for the flute, stating, "I'm always reluctant to persevere in writing for an instrument I can't abide."
The Clarinet Concerto in A major K 622 was the penultimate piece Mozart entered in his autograph work-list.
The autograph scores for Mozart's Clarinet Quintet and Clarinet Concerto have been lost, and early printed editions adapted the part for a standard clarinet.
Mozart wrote his Clarinet Concerto in A major K 622 for his friend Anton Stadler, a clarinettist who was close to the composer throughout their years in Vienna.