The prestigious symphonies and orchestras of the Bay Area often fail to attract a young or diverse crowd — but it’s not because wealthy people are the only ones who appreciate classical music. That was the thinking behind Groupmuse, a music startup founded by a group of recent college graduates who wanted to make chamber music accessible and affordable for a much wider audience. Modeled after casual house-concert gatherings during their college days, the Groupmuse team members bring chamber music concerts to people’s living rooms throughout the Bay Area. The result is a win-win for musicians and crowds. The audience gets a very intimate concert during which they can chat with the performers and share snacks or a bottle of wine with the strangers next to them on a comfy couch. At the same time, the musicians get a chance to play for young, enthusiastic crowds in quiet settings at which the nuances of their performances shine through in a way that is impossible in a giant concert hall. In the East Bay, where house concerts remain a staple of the underground music scene, Groupmuse provides an inviting and welcome addition.