"THIS GUY CAME UP to me and said, 'Do you sing "Fascination"?' and I said, 'Gee, I'm sorry, sir, I don't sing it,' " recalls pianist Judy Roberts of a 9 p.m.-to-5 a.m. gig in a Chicago bar back in the '60s. "The bartender, who was a friend of this guy, took this gun out and slapped it down on the bar and said, 'Listen, sing "Fascination." ' So of course I sang it." On the way home Roberts, whose professional role up to that point had been strictly as a pianist, said to herself, " 'Goddam, if I can sing 'Fascination,' I can sing all these songs I've been hearing Jackie Cain and Roy Kral do and Nancy Wilson do and Annie Ross do' -- and the next night I was a singer."

Roberts will open tonight in the Piano Room of Cates Restaurant in Alexandria with Jim Cox, one of the last bassists to work regularly with the late Earl Hines. The duo will remain in residence there Tuesdays through Saturdays until Sept. 22.

"My father, whose name is Bob Loey, is a terrific guitar player and singer," explains Roberts, "and he grew up in the big-band era, did arranging for Fletcher Henderson, played with Muggsy Spanier, Israel Crosby and those kinds of people, and he knows a million tunes and has a great ear. So I was born into a complete musical setting, and in lieu of material things, which we definitely didn't have, we just sat around and played piano and guitar all day as recreation. By the time I was 8 years old, I must have known a couple of thousand songs by osmosis, and that is why to this day I don't hardly read at all. For a game my father would say, 'Okay, let's see if you can figure out the chords to "Tenderly," ' and I would figure them out by ear. I remember pictures of me sitting on the piano with my feet on the keys, like about 8 months old or something, and my dad playing. In the middle of a gig, if I get hung up on a tune, I call my parents and one of them can sing the entire song to me. My mother can sing the bridge or any part of any song -- she just has a retentive memory for it."

With such strong roots in the Windy City, Roberts has retained Chicago as her base, although she spends a lot of time on the road -- touring Japan, playing European festivals and traveling throughout the West and Midwest of this country. With a fourth album out this spring (on Pausa, with Ray Brown on bass, Jeff Hamilton at the drums), Roberts has played only one engagement east of Cleveland, at a restaurant in Cherry Hill, N.J., a decade ago.

"In high school I was already a weirdo," Roberts confesses, "the class beatnik. I was listening to pianist Andre' Previn, and everybody else was listening to the pop garbage of the day. So I was an outcast, a poor, Jewish outcast." She laughs. "You know how little girls want to be movie stars? Me, I was dying to play piano, but I didn't know any women that were doing it, I couldn't see any role models. I was dating a jazz bass player and he was working at a coffeehouse in the suburbs. One night I went out there with him and the piano player didn't show up, so guess who sat in. The owner said, 'Hey, this is great, a girl piano player!' I was hired, catapulted into a coffeehouse job at the age of 15. People say, 'Weren't you discriminated against as a woman?' No, just the opposite. The gig was dependent on pleasing this owner, who decided that a girl piano player was a commercial commmodity."