New Amsterdam Records, a new label run by composers, has begun documenting this hybrid music, with invigorating discs by the band itsnotyouitsme and the composers Corey Dargel and William Brittelle.

Orchestras seem content to be museums now, even as they wring their hands about dropping subscription sales and graying listeners.

Whether a listener absorbs this music or rebels against it is at least partly a matter of how the performers put it across. It would be hard to imagine an ensemble playing it with greater virtuosity than the JACK Quartet, which seemed not merely earnest but also completely comfortable with, and passionate about, the strange sound worlds at hand.