Hearing an ensemble perform Beethoven's Große Fuge, Op. 133, in a neighbor's basement was so moving that Sam Bodkin pledged to expand listenership of chamber music. When he moved back home to suburban Boston after graduating from Columbia University in 2012, he started Groupmuse and began hosting local gatherings--once a week at first, which soon became eight or nine times a week.

The Groupmuse app brings live chamber music to living rooms. "Despite our many technologies, there just aren't enough opportunities to gather in the real world around something meaningful and sublime," says Bodkin. Launched in 12 cities, including New York, Philadelphia, and Portland, Oregon, the website and app help music lovers find a concert, for a $3 fee--or host one. At the host's home, tables are pushed aside, and the show typically begins around 7:30 p.m. Attendees pony up at least $10 each, which goes to the ensemble. For some events, Groupmuse guarantees at least $100 per player; in 2018, musicians averaged $155 each per event.

Groupmuse has organized about 4,000 shows. It also helps Carnegie Hall and other institutions sell tickets to undersold shows, and has begun to host weekend retreats. The three-person company, which raised $240,000 from Kickstarter and private investors, is now becoming a cooperative that will give equity to the musicians on its platform.