SAN JOSE, Calif. — Every night, Jason Harvey pushes Madonna's buttons.

No, he's not the pop diva's latest boy toy. He's "the video guy."

Backstage, the 36-year-old engineer from Milton Keynes, England, works multiple keyboards in a booth that is a virtual traveling TV station. This is where he pushes her buttons. Using software from Adobe Systems, he sets in motion multiple video streams that fill giant screens over, around and beneath the one-inch Plexiglas stages that the preening Madonna dances on.

"The biggest one is at the end. You mess up and the show wouldn't end properly. That's the one I always worry about," Harvey said hours before Madonna's second San Jose performance last week at the HP Pavilion, and minutes before the 47-year-old cultural icon breezed by for a sound check.

Harvey, with spiky, red-tinged hair and sporting a "The Who" T-shirt, would slip unnoticed through any fan gauntlet. But he is much more than a tech roadie. In this multimedia age, Harvey is someone Madonna would not want to miss the bus — or jumbo jet. With "Confessions" tour ticket prices that start at more than $100 — stage-hugging seats to Madonna's shows go for $350 — fans expect an experience more akin to a Broadway extravaganza than a pop singer strumming a guitar on a stage.

And in this video-everywhere world, where 9-year-olds are posting their own cinema verite on Web sites like YouTube, a performer, especially of Madonna's stature, who doesn't offer a seamless and sophisticated big-screen experience is like a singer out of tune.

"The audience expects a multimedia artist because they are multimedia consumers," said Tom Randolph, president of FrameFree, which makes digital imaging software used by bands, DJs and club owners. "The new bands, the indies, have to do it or else they won't stand out."

Video accompanies 21 of Madonna's 22-song concert and includes a montage of President Bush, Vice President Dick Cheney, Saddam Hussein and North Korean leader Kim Jong Il, a sketch of the New York skyline that appears to be drawn real-time as she sings "I Love New York," and a rider falling off a horse, referencing her 2005 accident.

Harvey's operation includes a nine-person crew, 22 hard drives, six digital video cameras and two miles of video cable. He manages images and video using Adobe Production Studio, a suite of software including Adobe's After Effects, Premiere Pro and Photoshop programs.

"It's the savior," Harvey said of the software. "Without it I'd be dead in the water. We would not be able to do our jobs."

The video setup for Madonna's shows was created during a 12-week development process, which included creating and selecting video produced by independent studios, choreographing the images with Madonna and her 22 dancers and last-minute "tweaks and twiddles." For each show, Harvey runs three identical versions of the video performance; should there be any glitch, he can switch to a backup in a mouse-click.

"There is no room for failure," he said. "The show has to go on."

Harvey, who once did TV and corporate production work, became a video rocker 10 years ago, a time when most of what he did was beam performers' images on giant screens at large venues.

"Ten years ago, we were very limited by the technology available to us," he recalled. "Digital was very, very expensive. You couldn't really take it on the road. Most of the playback was controlled by VCR machines and laser disc machines."

Harvey, whose business is called Short & Spikey (www.shortandspikey.com), has since worked with numerous pop artists, including Cher, Paul McCartney, Pink and Elton John.

Madonna's journey to the stage is like a trip to the office: She's all business.

"The lady is a perfectionist," he said. "She works 110 percent, and that's what she expects from all of her people."

Shortly before showtime, Madonna, sporting her trademark designer track suit, dropped by the video crew. "She said 'hi' to everybody and 'Have a good show.' We were all quite shocked," said Harvey, who noted the queen of pop tends to keep to herself. "It was lovely to hear."

All artists, though, have one thing in common: They want control, and can sometimes have an uneasy relationship with technology, approaching streaming images to a Web site or mobile phone very cautiously.

"They are normally pretty outspoken about what they want — and don't want," said Harvey, who likes to fiddle with different video effects, sometimes to the chagrin of the pop stars.

He has been told, "If you ever show that again, you are going to die — or something unprintable," he added. "Some days you have to step over the line to be told never to do that again. That's part of being creative."