Musical tastes and audiences are central themes in the sociology of arts and culture. While the literature has focused extensively on the sociodemographic composition of music audiences, little attention has been paid to the hidden work of concert promoters, in charge of making music public and framing experiences of musical performance. Based on an ethnographic investigation of Sofar Sounds, this chapter outlines what a sociology of music audiences from the perspective of concert promotion might be. Sofar Sounds is a music event company that has built its project and brand on its ability to gather “attentive” and “open-minded” audiences. I analyze four devices that Sofar Sounds uses to create and maintain a specific form of audience: (1) secrecy, (2) invitation, (3) intimacy, and (4) the continuous capture of spectators’ attention. I conclude by exploring how concert promoters compose an ecology of live music and make music an experience for the audience.