When guitarist Mike Buckley first became known around town in the mid-'90s as a player in the popular teen-punk band Vivid Imagination, it would have been impossible to predict where he'd wind up circa 2004. Now a seasoned, if low-key, veteran of the Denver scene, he's carved out a much more cerebral and challenging niche with his current project, Nightshark (appearing Monday, July 26, at the Ogden Theatre with Sonic Youth and Wolf Eyes). Abetted by drummer Andrew Lindstrom and saxophonist Bec Mhalek, both of the jazz quartet General Populace, Buckley pries open his instrument and dives deep into the furthest reaches of shuddering atonality and free improvisation, citing as inspirations artists as diverse as John Zorn, Steely Dan, the Melvins and Ornette Coleman. Nightshark has yet to put out a disc of its own, though Buckley has recently released two solo full-lengths of lo-fi experimentalism under the name Tres Quatro. (The albums appear on the NGWTT imprint run by the members of Friends Forever, who frequently record and collaborate with the guitarist.) Warming up the stage for Sonic Youth is surely a daunting task, but Nightshark, as unnerving and relentlessly in motion as its namesake, should have no problem holding its own.