Buffalo Collision. Photograph courtesy Monterey Jazz Festival.

The Monterey Jazz Festival took an abrupt turn into the avant-garde when Buffalo Collision, a unique combination of two advanced strains of freeform jazz, took the Garden Stage for the space between Sunday’s afternoon and evening programs.

On the one hand were pioneering saxophonist Tim Berne and free cellist Hank Roberts. On the other, Ethan Iverson and Dave King, two thirds of iconoclastic trio The Bad Plus. Together, they made deeply challenging yet rigorously logical music.

Berne stood off to the side, facing Roberts’ position at center stage rather than the audience, whom nobody seemed to acknowledge. When a small jet screamed overhead early in the performance, Berne took it as a signal, replying with a harsh screech that kicked the ensemble from quiet musing to agitated action. He bounced on his toes as the energy rose to a fevered pitch, his alto sax lines focusing into a tense beam. At one point, Berne dropped a plastic water bottle into the bell of his horn, producing a high, keening scrape. At other times, he probed with stretching squeaks and ducked back into fragments of boppish melody in an ever-shifting mix.

Roberts gripped his cello sidewise brtween his legs, arcing or bunching his body as he bowed melancholy passages or low scribblings. Soloing, Roberts sustained a skritchy scribble or drifted into Asian-toned atmospheres, occasionally squeezing down on his instrument as if to asphyxiate it.

Dave King ranks with Han Bennink as one of the world’s most visual drummers. Even when playing almost nothing, he appeared mere seconds away from smashing his kit to splinters. But for the most part he played quite a bit, laying down thick rumbling carpets or madly piling percussive noise on top of the others’ solos. And pianist Iverson painted the scene in dissonant shades and umbral tones, alternating widely spaced, unadorned chords with meandering strings of notes that navigated dark labyrinths like Ariadne’s mythical thread.

Such alien noises were too much for most folks. Few ventured into the Garden Stage area, fewer stayed for more than a few minutes. But those who remained got an earful. Bravo to the Monterey Jazz Festival for bringing this exceptional group in from the fringes.