Not content with one Mariah Carey singing her Christmas classics this season? How about two or maybe five? The pop star gave a virtual performance simultaneously across five major European cities on Thursday evening. 　　On-lookers in Frankfurt to Krakow watched a life-sized hologram of the singer giving renditions of hits including "Oh Santa" and "All I Want For Christmas Is You". 　　The projection of the singer's body was joined on stage by four real-life dancers, who were unveiled to the crowds from a giant gift box. 　　Filmed on a single fixed-camera in a New York Studio prior to the event, the Grammy-winning singer said the technology was a real eye-opener. 　　Mariah Carey: "For the fans it's something where they can feel more involved, they can feel like they're with you they're live cause regardless I'm singing to the fans everywhere in the world doing this you know I mean everybody where it's been broadcasted everybody through T-Mobile so I'm all about my fans and this was a way to bring everybody a bit closer. 　　" Mariah is looking forward to celebrating the holidays with new-born twins Moroccan and Monroe, who she gave birth to earlier this year. 　　Mariah Carey: "They really respond to music. I sing to them a lot and I'm looking forward to the first time they can come to a concert. 　　" With more than 200 million albums sold worldwide, it seems Mariah will be around a long time yet, especially as her self-penned "All I Want for Christmas Is You" was re-recorded with Justin Bieber for his new album "Under The Mistletoe".(Lisa Giles-Keddie/Reuters)