In my idiosyncratic personal dictionary, the current definition of the word “omnimusician” is a little different from the one you might’ve found there ten years ago. At that point, it would’ve meant someone who plays all kinds of creative music—free, composed, conducted, acoustic, electronic. Now the term applies to a different kind of figure, one who not only pursues an interest in many different approaches to playing music but also takes a multifarious role behind the scenes. For these folks, a whole batch of whom now live and breathe as if there were never any other way, making music also requires making music possible. And documenting it.

Dave Rempis/Ingebrigt Håker Flaten/Avreeayl Ra + Jim Baker Quartet Sun 9/1, 4:15-5 PM, Jay Pritzker Pavilion

From very early on, Rempis wasn’t satisfied to sit and wait for the phone to ring—he knew, as he started to organize and lead his own ensembles, that he’d need to hustle. Further, he knew that the hustling wouldn’t always be on his own behalf—he’d need to help fertilize and nurture the improvised-music community as a whole. So in 2002, he began booking a weekly series through the nonprofit Elastic Arts Foundation. In his subsequent 17 years of service (he’s now president of Elastic’s board), Rempis has added countless seminal gigs to Chicago’s improvised-music history, providing a consistent outlet as other venues came and went.

Baker is the ultimate wild card. He’s the unexpected turn, the twist in the story, the surprise witness. Whatever you think he’ll do, think again. On ARP synth or on piano, Baker is one of Chicago’s true originals, his greatness rarely hailed as loudly as it should be. And in this group, true to form, he adds mystery and humor and intrigue to the action, complicating the groove, interrogating the motifs, eavesdropping on the ensemble’s ESP. “Jim’s one of my favorite improvisers because he actually improvises every time and doesn’t just do his shtick,” says Rempis. “All three of them have ridiculous ears, and the ways in which we’re able to anticipate one another’s decisions are pretty astounding at times. In the first 30 seconds of the new record, I hit a tonic and then immediately jump up an octave to the flat ninth, which is somewhat of a weird choice. But Jim beats me to the punch by a split second, hitting the same flat ninth.”