Groupmuse aims for âstructural changeâ with switch to musician-owned business model By A.Z. Madonna Globe Staff,Updated April 1, 2021, 2:44 p.m. Email to a Friend âWeâre really targeting musicians who arenât necessarily taken care of by larger institutions," said violinist and Groupmuse artist Kiyoshi Hayashi.Suzanne Kreiter/Globe staff Quick, imagine a string quartet concert in a private home. Marble floors, vaulted ceilings, and uniformed servers with hors dâoeuvres platters probably come to mind. But this was rarely or never the case with the private concerts organized through the buzzy classical music startup Groupmuse, which matched musicians with music lovers â often younger than those in the typical Symphony Hall audience â who hosted casual, intimate concerts in backyards and living rooms.