NOTICE: Band at Work. Tracking a new jazz group's progress can provide as much fulfillment as discovering a young star. And while you won't find any phenoms in Kelly Brand's latest project--which comprises a slew of youngish jazz veterans--you will get an impressive enough progress report. Last year Brand broke up her long-running, eminently solid quartet; rising from the ashes, this new three-horn ensemble allows her to muscle up her writing. What's more, it seems that Brand has kept herself especially open to the feedback provided by her top-drawer soloists (saxist Jim Gailoretto, trumpeter Art Davis, and bass trumpeter Ryan Shultz); when they work out on her tunes, they suggest different directions, and their input should help her grow as a composer. As a pianist Brand has always used an odd mixture--blunt ideas and a polished attack--to reasonably good advantage. But her playing takes on added luster in the company of her longtime rhythm section, husband Kelly Sill on bass and Phil Gratteau on drums: because they know each other so well, the three instruments interweave like vines on a brownstone, creating a trio both sturdy and supple. Saturday the band concentrates on the careful compositions Brand started writing last year (which helped inspire the band's formation), as well as tunes by Sill and Gailoretto; on Friday Gailoretto sits out and vocalist Suzanne Palmer steps in, adding standards to the repertoire. Palmer remains among the city's most talented and enigmatic vocalists: she has never quite decided whether to go for jazz or pop stardom, although she certainly has the technique and daring to achieve either one. Friday, 9 PM, Green Mill, 4802 N. Broadway; 878-5552. Saturday, 10 PM and midnight (alternating with Kimberly Gordon and Chris Foreman), Bop Shop, 1807 W. Division; 235-3232.