Pittsburgh has had its skirmishes in the digital music wars over the replacement of live music with synthesizers and recordings. Now there's a parallel phenomenon -- actors facing off with their virtual counterparts.

The magician Prospero is ideal for multimedia treatment in 4D Art's production of "La Tempete." Click photo for larger image. 'La Tempete' (The Tempest) Where: Presented by the Pittsburgh Cultural Trust at Byham Theater, Downtown. When: Fri.-Sat. 8 p.m. Tickets: $20.50-$32.50 at Box Office at Theater Square, www.pgharts.org or 412-456-6666.

That's the alarmist view. Actually, virtual actors have been long among us, ever since film and TV replaced the live actor with a recorded image. But recently virtual actors have upped the ante, stepping down and out from their screens to encounter live actors in real space.

And at last Pittsburgh is getting its first look at one of the pioneers in this mixed medium, when 4D Art, an experimental Montreal-based creator, sets up at the Byham for a two-day visit of its high-tech, hybrid "La Tempete," in which live actors share the stage with holograms.

The play is, of course, Shakespeare's famous "The Tempest," in which the usurped Duke of Milan, the magician, Prospero, brings his enemies to the secluded island that he shares with his daughter, Miranda, and two spirits, the ethereal Ariel and beastly Caliban. The story centers on Prospero's struggle through vengeance to forgiveness.

4D Art was founded in 1983 and has been creating mixed media theater pieces and actively touring the world. But its earlier shows were less verbal, relying on dance, music, abstraction, lyricism and fantasy. This is the first time it has adapted a famous text.

"The Tempest" is a natural candidate for this transformative process, according to Victor Pilon, interviewed by phone from Montreal. "It is one of Shakespeare's most magical pieces, and we play a lot with illusions," he says. Much of its appeal is in the exercise of Prospero's magic. But Pilon and his co-artistic director Michel Lemieux (with whom he works also with Cirque du Soleil) and director Denise Guilbault take the interplay between real and virtual a step further, seeing it as a metaphor for the transformation at the heart of the play.

"La Tempete" uses just four live actors. Three play Prospero, Miranda and the difficult double of Caliban and Ariel. All the passengers on the ship which Prospero ensnares in his tempest appear as holograms, including his usurping brother, his brother's confederate King of Naples, that king's son Ferdinand and the inevitable comic figures, Stephano and Trinculo. So you might say all these exist primarily as images in Prospero's magical mind.

But gradually Ferdinand is redeemed from virtuality by Miranda's love. Played by the fourth actor, he then crosses over into hers and Prospero's real world.

What does this all mean technically? The ship characters were recorded and are projected as holograms, which we can see but the live actors cannot. So they must interact with them according to an unvariable script. But as Pilon describes, the actor playing Ferdinand is backstage in a virtual studio (or perhaps a studio of virtuality), so his projected hologram is "live" and can react to Miranda as she can react to him or at least the sound of his voice.

Although "La Tempete" relies on wordless, New Age stage magic, the language it speaks is French, with projected titles translating back into Shakespeare's English. This is because, Pilon explains, "La Tempete" was originally commissioned by a large French-language theater in Montreal. For an English-speaking audience, the language may offer a further dimension of mystery and dream such is appropriate to a magician's vision.

Pilon is most lyrical himself about the emotional theme of the play: "What a visionary Shakespeare was, [with his] understanding about humanity. ... At a certain age, I'm 48, you want to make peace with your demons. This [forgiveness] is very pertinent in the world today. Prospero must grow more tolerant and wiser."

His being stuck on that island is an outward sign of his anger. He has to earn his freedom, just as "Ferdinand incarnates himself into a real human being through the love of Miranda." As Pilon notes, that's not just fantastical in a world where people fall in love over the Internet with people they have never seen.

At last Pittsburgh is going to meet one such suitor, 4D Art.