The most remarkable trick at this year's Grammy Awards was not the dress that held Mariah Carey's chest in check but the appearance of virtual band Gorillaz performing “live” on stage with Madonna. Any theatre rat would recognize the performance as an elaborate, 21st century take on Pepper's Ghost, the theatrical illusion in which an image or an actor offstage is illuminated so that the light waves bounce off a reflective material placed at a strategic angle onto an onstage screen, creating what looks like a ghostly image onstage.

“A 21st century take on Pepper's Ghost is correct,” explains James Rock, director of Musion, the UK-based company responsible for the effect (www.musion.co.uk). “The principles remain the same. I don't think the laws of physics are likely to change soon, but the development of HD video projection, coupled with high powered projectors and the use of a thin membrane foil, have created reflected images that have a much more realistic look than anything previously achieved using a more conventional Pepper's Ghost setup.”

The backbone of the Grammy effect (and, indeed, of other televised Gorillaz performances to date) is the Musion Eyeliner system, which is composed of a video projector, usually DLP, with a minimum native resolution of 1280×1024 and a brightness of 5,000+ lumens, a hard disc player with 1920×1080i HD graphics card, Musion's patented Eyeliner foil, a 3D set/drawing that encloses three sides, plus lighting, audio, and show control. The content can be live, virtual humans, or any variety of objects and has, thus far, been used extensively in the corporate market for product launches and the like. The company has secured several worldwide patents based on the process, with the Eyeliner foil being a core component.

“The foil is one of the keys to the technique,” says Rock. “Suffice to say, it is supplied on a large roll — 16' or 32' high and hundreds of feet long from our supply source — and has a high gain reflective treatment that's applied to it during production. The foil is also very thin but quite durable to work with. This means that we can do very big images where glass isn't a practical option.”

The Grammys performance was a variation on the MTV Europe Music Awards in Lisbon, with the added attraction of a virtual superstar. Yes, that's right. The Madonna you saw on stage with Gorillaz at the Grammys was a virtual as her cartoon counterparts. However, the rappers from De La Soul who came onstage were, in fact, the real deal.

“The Grammys collaboration with Madonna was born out of the Grammy production team seeing the MTV show and recognizing the great opportunity to show live cartoon characters with a virtual superstar as well as the live performers (De La Soul),” says Rock. “It was done so well that I still think a lot of people missed the real trick with Madonna. Most people I've spoken to think that she was real on the Gorillaz stage.”

Madonna's performance was filmed three weeks prior to the Grammys, and the production team showed her a route to walk so they could drop in Gorillaz in post-production. The animated characters are the work of Tank Girl cartoonist Jamie Hewlett, who collaborates with Gorillaz founder Damon Albarn. Actual footage was created by UK-based animation house Passion Pictures. “They worked out the synchronization and, I imagine, slightly adapted the animation to make it look as though there was real interaction with Madge,” says Rock.

Gorillaz has also announced plans to collaborate once again with Passion Pictures to produce a full live holographic tour for 2007-2008, or perhaps, a better description is that there may be several tours, since the members can be duplicated at will. Concert producers, take note.