Nick Cave and Julian Casablancas are changing the way fans communicate with artists. This is a very good thing.

It was midway through the Bad Seeds’ set at the Los Angeles Forum when Nick Cave, the band’s indefatigable lead singer, who’d slid and skated about the stage to a thronging sea of hands clasping and grasping after him, the movement some surreal synchronicity akin to those mesmeric flocks of starlings…