Supporting a new disc called "Holon," Ronin operated without its clarinetist, Stefan Haslebacher (who goes by the name Sha), who was stuck in his hotel room with the flu. But it didn't matter much. Bärtsch, electric bassist Björn Meyer, drummer Kaspar Rast, and percussionist Andi Pupato mesmerized us with such deep grooves that it seemed as though one mind controlled eight hands.
Ronin's sound is clean and crystalline. It emphasizes the percussive force of the piano as much as the melodic, to the point where Bärtsch spent a lot of time with his left hand inside the case, pressing on the strings to reduce the vibration as he played the keys with his right hand. He often started a piece by creating a circular, two-bar figure, slowly luring in the rest of the rhythm section.
The effect was almost an acoustic counterpart to ambient or techno music; patterns repeated and evolved little from measure to measure, but over the course of a tune they dramatically altered themselves. Intensity levels crested and dropped like ocean waves. The pianist occasionally played in a different time signature than his colleagues, but every few cycles they met up, like planets orbiting the sun at varying rates. The emphasis on aesthetic over songwriting and soloing was clear - each piece depended on the musicians' ability to shift ever so slightly and to adapt to the others' changes. Chords were scarce. Scales were employed, yes, but - without any solos in the traditional sense - this was not modal jazz of the Miles Davis/Herbie Hancock school.
In fact, Bärtsch doesn't even title his songs. Underscoring his minimalist approach, Bärtsch instead assigns them numbers: "Modul 42," "Modul 46," and so forth. It's sometimes not entirely clear where one tune ends and another begins; the blending is part of the idea. What matters is the groove, one that is unlike anything you've heard from any groove-jazz band ever before.
It transfixed Thursday's audience to the point where they wouldn't let the band leave. The first encore seem planned. But when the musicians left the stand a second time and the lights began to go up, the crowd protested with great vehemence. And so Bärtsch and company gave them what they wanted: more.
Steve Greenlee can be reached at greenlee@globe.com.
