Of course, this concerto was not written for the clarinet. It was written for the basset clarinet, a very rare instrument that didn't survive the turn of the century (1800). Indeed, there exists a complete piano sketch of the first movement for the even rarer basset horn in G. Mozart settled for the basset clarinet in A, most likely because the targeted performer, Anton Stadler was touring with this instrument. The basset clarinet goes down to written C instead of the normal E, sounding A. What this means is that all of those low arpeggios that sound contrived on a normal clarinet because of the forced inversions suddenly sound natural and correct when played on the basset clarinet.

LeBlanc currently catalogs a basset clarinet, which is their normal professional instrument with an extended foot joint. A few touring pros, Sabine Meyer, for one, have made recordings with this instrument, but the recording that you want to get is the old Christopher Hogwood / Anthony Pay versions, still available on Decca. Pay plays a replica of Stadler's instrument, and the results are astounding.

While the concerto is a cerebral and learned, the quintet is just plain fun. The final theme and variations is my favorite. Incidentally, the quintet was also written for Stadler's basset clarinet, but I have never heard a recording on this instrument.

Bob