No discussion of Mozart's chamber works would be complete without mention of his Serenade No. 10 for winds in B flat major ("Gran Partita"), K. 361. Amazing music that as Salieri is purported to have said is "like listening to the voice of God". Of special note is his use of a pair of basset horns; a seldom heard instrument, member of the clarinet family, which is essentially an alto clarinet in the key of F. A beautiful sonority that perfectly fills in the harmonic "gap" between the clarinets and the bassoons. The Charles Mackerras/Orchestra Of St. Luke's recording on Telarc is very fine on all counts. Highly recommended!
BTW, on the subject of insanity and the power of Mozart's music: I swear that only Mozart can get my pet parrot to sing along.