Rock fans of a certain vintage have fond memories of the “family trees” drawn by British journalist Pete Frame, which lovingly chronicled the evolution of an act through the musical histories of its members. Some were as complex as biblical genealogy, with band begetting band across several generations—but that’s nothing compared with the musical bloodlines on display whenever the Globe Unity Orchestra takes the stage.

Globe Unity is as much an ecosystem as a group, with connections that span the entire history of European improvisation, the early days of Germany’s kosmische musik scene, and the New York City noise underground of the 1980s. Founded in 1966, it was the first avant-jazz big band outside the United States, and nearly 45 years later pianist Alex von Schlippenbach remains its main organizer and guiding force. His contributions are not to be taken lightly—although, as he says in an interview from his Berlin home, running this musical juggernaut is not quite as taxing as it was during the turbulent ’60s.

“I think it’s quite an easy thing for me now,” he notes, in precise but heavily accented English. “My role in the band does not have too many problems, because the musicians know exactly what is happening. I don’t have to say too much.”

Simplifying his task, no doubt, is that the current incarnation of the Orchestra is devoted entirely to improvised music. In its earlier years, Globe Unity showcased compositions by von Schlippenbach and other key members, as well as politically charged classics by ’30s radicals Hanns Eisler and Kurt Weill. Now, though, all of its music is made up on the spot.

With 11 members on-stage—including such seismic forces as drummers Paul Lovens and Paul Lytton, saxophonist Evan Parker, and trombonist Johannes Bauer—how does the band steer clear of chaos?

“It’s a good question,” von Schlippenbach says thoughtfully. “Sometimes we have an idea how to start, like building up an improvisation on just single notes, or building it up on long sounds. But about the ending we never talk. The organization of the music is somehow happening from itself.”

It’s functional anarchy—and, as von Schlippenbach contends, an oddly uplifting sound.

“I have to mention a very nice compliment I got from an older lady,” he says. “She said, after listening to a concert, ”˜Your music is a good Antidepressivum,’ meaning a good medicine against depression. I liked this compliment very much. Responses like that are another reason to go on!”

The Globe Unity Orchestra plays the Roundhouse Community Arts Centre on Sunday (June 27), after the Schlippenbach Trio, featuring Evan Parker and Paul Lovens, plays the same venue on Saturday (June 26).