After singer Jackie Allen first recorded with pianist Judy Roberts–on their self-produced 1998 Christmas album, Santa Baby–you had to wonder why it hadn’t happened sooner. Both local regulars, they’ve gigged together on and off for most of the decade; Allen’s light, buoyant voice makes a lovely match with the bright harmonies and bouncy Horace Silver rhythms of Roberts’s piano style, and when they both sing, Roberts’s polished-brass clarity complements Allen’s more ethereal, yearning tone. Roberts, a 30-year veteran of Chicago clubs, has been at the top of her game since the late 80s, maintaining a mature and satisfying balance between her serviceable technique, enthusiastic imagination, and keen musical wit. And the generosity she’s always shown other musicians extends beyond her gracious accompaniment: she lends moral support, and sometimes even her sidemen, to latecomers like Allen, who moved here from Milwaukee in 1990. Since Allen’s one and only album as a leader (Never Let Me Go, on the short-lived Lake Shore Jazz label) appeared five years ago, her artistic growth hasn’t been well documented; as a result, the textured readings she gives slower numbers and the power she attains at full throttle may take some listeners by surprise. (At the marathon “Women Who Swing” showcase in March, her ballad work stilled the packed house.) Allen has also written or cowritten a number of memorable tunes–three of which appeared on the Lake Shore album–and with any luck she and Roberts will have worked up a few of them for this performance, which caps the opening night of the “Jazz at Ravinia” series. The program, which starts at 6 PM, also features Jerry Coleman’s Nineburner, the Ramsey Lewis Trio, and Wayne Shorter and Herbie Hancock; Allen and Roberts go on at 11. Thursday, June 10, Ravinia Festival, Green Bay and Lake Cook Rds., Highland Park; 847-266-5100. NEIL TESSER

Art accompanying story in printed newspaper (not available in this archive): photo/James Risch.