Tribute acts

When it comes to musicians and fans, the former are (inevitably) more often in the spotlight, literally and metaphorically, than the latter. And yet fandom - its forms, its eccentricities, its excesses - can be fascinating, and books such as Molly Tie's Rebel Grrrls productively shift the focus from those on stage to those in the audience. The Holy Pop! exhibition currently on display at Somerset…