Until last year, the gig situation for contemporary classical music—an emerging form called new music by its practitioners—had groups renting space and lugging their equipment to concerts. But Peter Margasak’s new- and experimental-music series Frequency, started in May 2013 at the Roscoe Village club Constellation, eased logistics and created a gathering place in the process. Now that there’s a reliable venue, the whole timbre of the scene has changed. “In the beginning, the idea was to create a feeling of community, that this was a hang,” Margasak says. “It’s definitely a scene. That’s been incredible.” Catch it Sundays at 8:30 p.m.