Corky Siegel's Chamber Blues was born in 1966, when Chicago Symphony summer conductor Seiji Ozawa, his Beatlesque hairstyle then a distinct novelty in the orchestral world, announced a desire to bring classical music and Chicago blues together. Siegel, the harmonica wizard behind the Siegel-Schwall Blues Band, has periodically revisited the concept ever since; his latest thinking on the subject will be on display at the Ark on Friday, June 17. Simply as a remnant of the idealistic 1960s that hasn't been completely trampled or corrupted, the Chamber Blues group — violins, viola, cello, percussion, and Siegel on harmonica, piano, and occasional vocals — would be worth seeking out. Yet Chamber Blues is more than just that.

Joining the language of the Mozart-era classical string quartet to that of the blues is very tricky, even though the two forms essentially share basic harmonic procedures. Mutual mimicry isn't fusion. Who would really want more than once to hear the classical string players trying to imitate Little Walter's harmonica? Or, for that matter, the harmonica playing Mozart?

Although Siegel has said that Chamber Blues represents a "juxtaposition" of classical music and blues — "two forms working together" — rather than a "blend," few of his pieces even approximate the basic sounds of either the blues or his classical models. Instead, he builds large, varied structures out of familiar bits of both languages. Bent blue notes may appear on any instrument; the so-called Alberti bass of the Mozart C-major piano sonata often taught to kids becomes the basis for a blues progression; a big backbeat may be taken pizzicato by the classical instruments. Classical and blues ideas are used to interrupt each other, often with delightful effect, and no two Chamber Blues pieces sound much alike. When Siegel does a straight blues, like "The Woofy Girl Stroll," the tone is often humorous. Indeed, much of the Chamber Blues music is witty, not bluesy, and some of the pieces have titles like "Opus 4 (12 of Opus 8)." On a spectrum between extemporized blues and notated classical music, Chamber Blues is somewhere in the middle: multipart refrains are clearly planned out, but there's a lot of freedom for the individual players.

The playing of percussionist Frank Donaldson is important to the realization of Siegel's ideas. Much of the time he uses a small Indian tabla drum, and not just because it's quiet enough not to overwhelm the stringed instruments — a gently played snare would do just as well for that. It's almost as if the interposition of a third voice helps to reconcile two musical languages that remain quite far apart. Corky Siegel's Chamber Blues may be among the more arcane musical acts to come to town this year, but this music exhibits some pretty original thinking that bears on the vexed question of how we might all get along.