Over the summer, I found myself at Hammerstein Ballroom surrounded by more than 2,000 ecstatic Vocaloid fans, each equipped with a color-changing wand (something between a lightsaber and those conical lights that ground control uses to direct runway traffic at airports). Without much warning, the crowd would sync up their movements in spontaneous choreography along with the music, which ranged in style from disco to rock to pop, and was played by a live band. But the band was fronted by a rotating cast of anime avatars in 10-foot-tall hologram form, each representing a different pitch of vocal-tuning software that literally anyone can purchase and create songs with.