Florence Welch knows the power of the voice all too well. She possesses a singular belt that adds an aching dimension to her rousing, elliptical pop; she headlines festivals and arenas for crowds that shout along with her lyrics in adulation. “I can come here and scream as loud as I want,” she wails on the jaggedly anthemic opening title track of her mononymic project Florence + the Machine’s Everybody Scream ; she’s specifically referring to the transformative nature of live performance in