Since it can’t compete with the sprawling Toronto and Montreal events in terms of overall scale, the Guelph Jazz Festival has instead concentrated on being adventuresome, which has earned it a unique place among Canadian festivals and consistently attracted international interest thanks to the deft and often radical programming. For its 15th incarnation, the festival draws its principal performers from a global community of experimental improvisers. ICP Orchestra (Instant Composers Pool Orchestra) has been an explosively creative part of the Amsterdam free-jazz community for more than 40 years, with pianist Misha Mengelberg, drummer Han Bennink and a host of associates conducting many original explorations, including post-modern interrogations of the works of Duke Ellington and Thelonious Monk. They’re joined on this double bill by Japa­nese pianist Satoko Fujii’s Ma-do, a new ensemble whose name is a play on mado, “window” in Japanese, and ma, the silence between notes. The quartet includes Fujii’s husband, trumpeter Natsuki Tamura, bassist Norikatsu Koreyasu and drummer Akira Horikoshi. Launching Ma-do’s first disc here, Fujii conceived the group as an ensemble that could better express her compositional interests in space, texture and silence. Sept. 5. $30. Main Stage, River Run Centre, 35 Woolwich St.

Sunday is devoted to the music of saxophonist-composer John Zorn, who’s joined by a brilliant team of associates that includes guitarist Marc Ribot, keyboard player Jamie Saft, electric bassist Trevor Dunn, drummer Joey Baron and percussionist Cyro Baptista. In the morning, the ensemble breaks up into micro-units for a program of free improvisations. Sept. 7. $25. Cooperators Hall, River Run Centre.

In the afternoon, Zorn presents a double bill of two closely related projects. Electric Masada employs Zorn’s Masada collection of compositions, comprising more than 500 short themes composed on ancient Jewish scales. With just a few alterations, the group becomes The Dreamers, Zorn’s stunning venture into the dynamics of lounge music, exotica, surf guitar and Latin jazz, providing an extraordinary canvas for Ribot’s virtuosic mastery of popular guitar idioms of the past half-century. Sept. 7. $40. Main Stage, River Run Centre.

Other performances include duets by turntablist DJ Spooky and pianist Vijay Iyer (Sept. 3, $30, MacDonald Stewart Art Centre, 358 Gordon St.), and guitarists Kevin Breit and René Lussier (Sept. 4, $25, Cooperators Hall, River Run Centre).

There’s also a day of free performances, starring Quebec’s l’Orkestre des pas perdus and concluding with Jane Bunnett’s Carnavalissimo, a celebration of Afro-Cuban jazz. Sept. 6. Upper Wyndham Street Jazz Tent.—Stuart Broomer