People in 300 cities around the world are hosting secret gigs in their living rooms

Whether it's an office in London, the top of a ski jump in Oslo, or a betting store in Manhattan, Sofar Sounds hosts secret pop-up performances in unusual spaces.

And for those willing to welcome strangers (and an element of surprise) into their home, hosting a gig with Sofar Sounds can even mean having artists like Bastille, James Bay, and Hozier playing in the comfort of your own living room.

With the company now hosting gigs in 300 cities around the world - and expecting at least 25,000 people worldwide to attend a gig in November - Business Insider caught up with cofounder Rafe Offer to hear about how what started as a hobby between music-loving friends in London has turned into what he calls a "global movement."