Maria Schneider Orchestra at Jazz Standard Maria Schneider doesn't play an instrument when leading her 18-piece orchestra, one of the most disciplined and flowingly expressive in jazz. But her kinetic contribution stamps each performance with expository force, a key to comprehension. Maria Schneider using sharp movements to articulate many of the nuances in her arrangements at Jazz Standard. Conducting the orchestra at Jazz Standard on Tuesday night, in the first set of her usual Thanksgiving-week engagement, Ms. Schneider used sharp, precise movements to articulate many of the nuances in her arrangements: a terse and rigorous semaphore evocative of certain modern-dance movements (dance is one of her extracurricular enthusiasms) or perhaps the alert, flittering stir of birds (bird-watching is another). Her physical presence was an essential factor in conveying the music. Not that the members of the band, professional to the core, had any trouble with their task. The execution among them held to a stratospheric standard, without ever crossing into the realm of the clinical. During the evening's opener, "Evanescence," the title track of Ms. Schneider's 1994 debut album, the brass and woodwind sections shifted from one chord voicing to the next with such undulant cohesion that it sounded like the mellow wheeze of an accordion's bellows. Ms. Schneider's current rhythm section includes an actual accordionist, Ron Oswanski, along with the pianist Frank Kimbrough, the guitarist Lage Lund, the bassist Jay Anderson and the drummer Clarence Penn. Strikingly, given the heavy concentration of chordal instruments - and Ms. Schneider's use of the rest of the orchestra as a rich color palette - the prevailing sensation was of openness. Ms. Schneider is rather famously a former protégée of Gil Evans, and this was one of his great strengths as a composer-arranger, an almost sleight-of-hand grace that she has adapted to her own use. There were other jazz-historical echoes, especially in the older material: "Gumba Blue," another track from "Evanescence," had the slinky gait (and the slangy double-time solo interlude) of a piece by the Thad Jones-Mel Lewis Orchestra. But the set confirmed Ms. Schneider's own ascendant stature as a touchstone for large-ensemble designs in jazz. More confirmation, for good measure: the line for her second set stretched up the stairs, out the door and down the sidewalk toward Park Avenue. Late in the set Ms. Schneider put in a plug for her forthcoming album, "Carlos Drummond de Andrade Stories," which she just recorded with the soprano Dawn Upshaw and the St. Paul Chamber Orchestra. This set included just one unreleased composition, the pastoral "Thompson Fields," commissioned through her Web site and featuring solos by Mr. Kimbrough (in a suspenseful rubato, faintly evoking the randomness of wind chimes) and Mr. Lund (assertively sleek, over a sort of "70s gospel-rock groove). Ms. Schneider typically took a seat during each long improvisation, leaving the soloists to connect freely with the rhythm section. But she rose to cue background annotations, like the urgent accents behind Marshall Gilkes's trombone solo on "El Viento," which closed the set. Here and elsewhere her ease of command was thrillingly transparent. It's a cliché to describe someone in her line of work as playing the orchestra as an instrument. Another way to put it, just as fanciful and no less accurate: the orchestra, in both its concept and its implementation, functions as an extension of her creative self. The Maria Schneider Orchestra performs through Sunday at Jazz Standard, 116 East 27th Street, Manhattan; (212) 576-2232, jazzstandard.net.