Vocaloid is a song synthesizer program created by Sony. What was once a vehicle for promoting a tool/game has taken flight as a pop phenomenon. The below video is a real capture of a Hatsune Miko concert. Hatsune is a holographic pop star who sings songs on stage with a live band. Many of the songs she sings are written by retail users of the vocaloid software. That consumer interaction is very cool. Virtual stars are not new to Japan with the Genki Rockets sporting un-named musicians and a fictitious lead singer named Lumi who is 18 years old and has never made the space flight to earth. If you need to know, the music by Genki Rockets is very approachable. Hatsune is like a cross between Sailor Moon and Lindsay Lohan.
It reminds of something that the Gorillaz did at the Grammies a few years ago, except Madonna was real and the audience was fake.
P.S. as Trevyn astutely pointed out William Gibson called this more than 25 years ago.