BISHOP-CLEAVER-FLOOD (Tuesday) As on a recent album, “Time and Imaginary Time” (Envoi), the saxophonist Andrew Bishop engages in an equal exchange with the drummer Gerald Cleaver and the bassist Tim Flood, expanding compositional frames and exploring open space. At 10 p.m., the Stone, Avenue C and Second Street, East Village, thestonenyc.com; $10. (Chinen)20090409
SYLVIE COURVOISIER AND MARK FELDMAN (Wednesday) Ms. Courvoisier, a pianist and composer, pursues intricacy; Mr. Feldman, a violinist, favors intensity. They have recorded together as a duo, which will be their format for the early set here, at 8 p.m. For the later set, at 10, they will enlist the bassist Eivind Opsvik and the drummer Gerry Hemingway. The Stone, Avenue C and Second Street, East Village, thestonenyc.com; $10 per set. (Chinen)20090409
MARK HELIAS QUARTET (Saturday) Mark Helias is a bassist of adventurous temperament and great rhythmic assurance, as he demonstrates in a band with two longtime associates, the trombonist Ray Anderson and the tenor saxophonist Ellery Eskelin, and a dynamic younger colleague, the drummer Gerald Cleaver. At 10 p.m., the Stone, Avenue C and Second Street, East Village, thestonenyc.com; $10. (Chinen)20090409
INGEBRIGT HAKER FLATEN (Friday, Sunday and Monday) Ingebrigt Haker Flaten is a Norwegian bassist, and one of the bigger fish in the pool of European free-improvised music. He’s staging a small-scale New York takeover this week, playing in two different places on Friday: first at Monkeytown (with the saxophonist Hakon Kornstad) and then at the 5C Café (with the cellist Daniel Levin). On Sunday he will appear in Double Heart, a group led by the saxophonist Tony Malaby; on Monday he will work in yet another duo, with the trumpeter Jawwaad Taylor. Friday at 7:30 p.m., Monkeytown, 58 North Third Street, Williamsburg, Brooklyn, (718) 384-1369; monkeytownhq.com; cover, $8, with a $10 minimum. Friday at 10 p.m., 5C Cafe, 68 Avenue C, at Fifth Street, East Village, (212) 477-5993, 5ccc.com; no cover, with a $5 minimum. Sunday at 8:30 p.m., Cornelia Street Café, 29 Cornelia Street, West Village, (212) 989-9319, corneliastreetcafe.com; cover, $10, with a one-drink minimum. Monday at 9 p.m., the Local 269, 269 East Houston Street, at Suffolk Street, Lower East Side, rucma.org; $10; $7 for students. (Chinen)20090409
PAUL MOTIAN OCTET + 1 (Tuesday through Thursday) A luminous and mysterious post-bop ensemble that consists of two contrasting pairs of improvisers (the saxophonists Chris Cheek and Bill McHenry, and the guitarists Steve Cardenas and Tim Miller); a couple of welcome stabilizers (Jerome Harris and Thomas Morgan, both bassists); a pair of wild cards (the violist Mat Maneri and the pianist Jacob Sacks); and a wily mastermind (Mr. Motian, on drums). (Through April 19.) At 9 and 11 p.m., Village Vanguard, 178 Seventh Avenue South, at 11th Street, West Village, (212) 255-4037, villagevanguard.com; cover, $20, with a $10 minimum. (Chinen)20090409
? SKIRL PARTY V (Saturday) Skirl, a Brooklyn-based label with a ruggedly experimental streak, celebrates its fifth anniversary with four bands from its roster: H-Alpha, an electro-acoustic trio with a new album called “Red Sphere”; the avant-folkish duo composed of the guitarist Mary Halvorson and the violist Jessica Pavone; the New Mellow Edwards, led by the trombonist Curtis Hasselbring; and Andrew D’Angelo’s Gay Disco Trio, led by Mr. D’Angelo, a strenuously upbeat multireedist. At 7:30 p.m., the Bell House, 149 Seventh Street, Gowanus, Brooklyn, (718) 643-6510, thebellhouseny.com; $12. 20090409
KEVIN TKACZ’S LETHAL OBJECTION (Tuesday) The bassist Kevin Tkacz (pronounced tax) features his own compositions in this adventurous and boisterous ensemble, with the trumpeter Ralph Alessi, the pianist Angelica Sanchez and, in his first outing with the group, the drummer Gerry Hemingway. At 7 p.m., Barbès, 376 Ninth Street, at Sixth Avenue, Park Slope, Brooklyn, (347) 422-0248, barbesbrooklyn.com; $10 suggested donation. (Chinen)20090409
TWICE TOLD TALES (Thursday) This expressive quartet, conversing mainly in terms of free improvisation, consists of the tenor and soprano saxophonists Tony Malaby and Louis Belogenis; the perceptive bassist John Hébert; and the ever-ebullient drummer Joey Baron. At 8 and 10 p.m., the Stone, Avenue C and Second Street, East Village, thestonenyc.com; $10 per set. (Chinen)