By DOUGLAS BRITT
Copyright 2007 Houston Chronicle

It's hard to say just what will happen tonight when Houston video artist Johnny DeKam and electronic musician Steve Nalepa get together at the Sabine-to-Bagby Promenade on Buffalo Bayou for a site-specific performance.

That's partly because the artists, who will be collaborating for the first time in Nights on Blue Bayou: City Soundscapes DeKam vs. Nalepa, aren't entirely sure what to expect.

"We're going into it without any preconception of what it's going to be like," DeKam said. "(Nalepa) knows my work; I know his work; we're going to show up that day, and we're going to just respond to each other."

They'll also be responding to the surrounding landscape, the water and the angular surfaces of the Sabine Street Bridge.

"It's a really big departure from a classic (video) projection situation where you have a big rectangle and then you compose for this very limited space," DeKam said. "Every surface is fair game for the projection, including the bayou itself, the river, the hillside, the sand along the bank, the concrete wall behind us, the ceiling, the undulations of the girders and the beams."

The promenade as a canvas is a natural progression for DeKam, who started as a gestural Abstract Expressionist painter during his undergraduate studies at Wayne State University in Detroit in the early '90s, only to forsake his brushes for computers as the dawn of techno captured his imagination.

He said he still considers his imagery "very painterly," but now he's "painting at 30 frames a second."

The technology to support DeKam's brand of improvisation wasn't around when he started working with computer-generated video, so he wrote his own software that enabled him to play video live in a performance environment.

Video-performance software is more common nowadays, but DeKam said Thursday's event will mark the U.S. debut of another new technology: video projectors with computer-controlled mirrors that can move 180 degrees on every axis.

"We can move video around freely and reposition it while it's playing, and we have four of these, so we have the ability to layer in different positions all over the architecture where (the imagery) goes," he said.

That means in order to take in everything that's happening, the audience will need to stay on its toes rather than settle into a passive experience.

"If they seem to be settling, I'm going to purposely move the video around so that they have to move," said DeKam, who's on the move himself these days, doing video production for the progressive metal band Dream Theater on its world tour.

The closest thing he has to a residence is a bed-and-breakfast in Houston, but he said he's likely to settle in Portland, Ore., after the tour wraps up in July.

The Los Angeles-based Nalepa said he'll be "improvising on the fly with a set sound palette"— chosen in consultation with DeKam — that will mix other artists' songs with his own productions.

His Web site, www.stevenalepa.com, says his music "combines deep dub bass, glitchy breaks, bioacoustic atmospheres and beautiful sinewave melodies to create his patented brand of ambient glitch dub."

The event is the last installment in a monthly fall series, presented by the University of Houston Cynthia Woods Mitchell Center for the Arts and the Buffalo Bayou Partnership, showcasing the bayou's new waterfront park.

Karen Farber, the Mitchell Center's director, said the site, with its juxtaposition of urban and natural environments, "encompasses what I think Houston is all about."

"You're looking at a natural waterway and a beautified, but natural, environment, but with the backdrop of Houston's downtown, which then is juxtaposed as well with this old, historic bridge," she said.

In addition to its architectural interest and its merits as a surface, DeKam said the bridge may allow the show to withstand another site-specific feature: Houston's unpredictable weather.

"At least if it's raining, we don't have to cancel, because all the equipment's going to be relatively shielded," he said. "If it's a light rain, a medium rain, people can bring their raincoats and umbrellas and still see the show, and maybe it'll add another interesting thing. The rain can catch the light."