A classic jazz stereotype--a staple of the jokes jazzmen tell among themselves--pivots on the lack of musicianship among female vocalists. Kimberly Gordon changes, in fact defies, the punch line whenever she takes the stage. She thinks like a musician; instead of displaying that mentality in a series of scat improvisations, she prefers to apply her burgeoning skills in swing and phrasing to the melodies as written. This approach allows her to showcase her round, dusky, indigo voice; if sapphires could sing, I imagine they'd have a similar sound. Hearing just a couple of tunes--or one headlong plunge to her voice's throaty bottom--lets you know that Gordon has listened extensively to Ella Fitzgerald. (Rather than model her, though, Gordon has mainly used Ella's example to exploit some similarities in vocal range.) Gordon hasn't got it all together quite yet: she tends to wrestle a bit with tempi, and the occasional clammed note pops up now and then. But even while she's developing into a probably terrific artist, Gordon presents us with a particularly soulful and invigorating style--well worth watching down the road, and also well worth hearing now. Saturday, 10 PM, Bop Shop, 1807 W. Division; 235-3232.