When it comes to programming, Concertante di Chicago, arguably one of the country's best and least heralded chamber orchestras, shows a great deall of savvy in making unlikely yet totally logical connections. Most recently, it's come up with this music-theater double bill. Written more than a century apart, Mozart's one-act opera The Impresario and Stravinsky's 1918 stage work The Soldier's Tale are both minor masterpieces about obsessions and temptations--even though one is a comedy, the other a cautionary tale. In the Stravinsky a Candide-like army deserter is tempted by an insistent devil to give up his violin, his only possession in life and a symbol of virtue. In the Mozart a hapless impresario, bent on putting on a show, has to pick between two dueling divas. The music of The Soldier's Tale is quintessential Stravinsky, filled with deft variations on popular tunes fom ragtime to Russian folk. The music of The Impresario shows Mozart at his most frivolous, turning the soprano arias into dazzling showcases of empty-headed virtuosity. Under the direction of concertmaster Hilel Kagan, the group will present condensed versions of both works: the eight-movement suite from The Soldier's Tale and The Impresario minus the largely unfunny speaking parts. In the Mozart, which features sopranos Elizabeth Futral and Pamela Menas, the audience will select the best diva. Also included is Mozart's Divertimento in F, which should provide an aptly relaxing entr'acte. Sunday, 3 PM, DePaul Concert Hall, 800 W. Belden; Thursday, 8 PM, Cove Auditorium, 520 Glendale, Winnetka; 454-3030.