Sometimes called the "clown of the orchestra" even by its devotees, the bassoon is basically a piece of arcane and complicated musical plumbing that nonetheless can produce real magic. It has the widest natural range of any wind instrument--four full octaves from a low B-flat to another...and then some--and the venerable South Minneapolis Bassoon Quartet (currently four witty women with a common satirist's heart) serves that spectrum with a repertoire that spans medieval madrigals, Bach, Henry Mancini, Scott Joplin, and "Mr. Sandman." The biennial public concerts, around April Fool's Day and Halloween, are reliable occasions for some wild humor, audience participation, and serious professionalism. Catch a concert, or book 'em (644-8816) for your wedding or bowling-league banquet.