Sofar Sounds, named for “Songs From a Room,” is a for-profit company that hosts live music performances in 340 cities worldwide. Founded in London in 2009 by three friends who were sick of the loud, disrespectful audiences at bars and rock clubs — this origin story is recounted before every show — Sofar now has a full-time staff of at least 50, investors like Virgin’s Richard Branson, and a team of unpaid volunteer “ambassadors” in every Sofar city. The company has grown quickly over the past eight years, largely by marketing itself as a grassroots movement for and by like-minded music lovers. Its motto is “Bringing the magic back to live music.”