Monday Night Jam by Martin Jones Westlin If you ever see flutist Bradley Leighton in concert, don't expect his body english to guide you through the beat. This man is not exactly metronome material. He hulks and sways and lurches markedly out of step when he plays, guided by the unseen forces that have made his instrument a hit since about A.D. 900, when those feisty cats from the Byzantine empire decided to lay down some serious live tracks. But that's jazz, the renegade stepchild for whom the exception is the rule. No other modern mainstream genre relies so heavily on improvisation to fuel it; no other performing musical art can float the term “fusion” with such conviction and poise. Leighton is thus permitted his idiosyncrasies – his quirky gyrations weigh heavily into his breezy take on his music and the concepts that swirl about it. On Monday, May 2, Leighton headlined an evening jam at a popular La Jolla eatery, replete with guest musicians and vocalists and their gifts for a waiting world. The Rancho Peñasquitos resident invited drummers Duncan Moore and Brad Rehm, keyboardist Allan Phillips, sax man Mikole Kaar and bassist Sly Simon along for the ride – the ensuing three hours were no less than a primer on the creation of solid gold. From a turn on Bobby Womack's light classic “Breezin'” to Phillips' maniacal mode of attack and everything in between, the music's seamlessness betrayed a mutual respect that transcends the pedestrian realm of key signatures and codas. Such untold unison in this improv-intensive climate – all the more remarkable amid Leighton's matter-of-fact declaration that he's never played with this collective as a group. “[Phillips] is cooped up in his studio all week,” Leighton explained, “just like a lot of these guys. When they decide they want to get out and play some funk, it's fresh, and it's new, and it all comes together. That's why you hire guys like these.” And that's jazz. Seattle-area native Leighton, 44, was raised on the likes of Earth, Wind & Fire and Tower of Power in his band days at Fife, Wash., High School. The jazz phenomenon would eventually captivate a young Army band alum in the early '80s as Seattle's after-hours clubs beckoned his pleasure. What followed was a body of work in rhythm-and-blues bands, Hammond organ trios, funk dance groups and straight-ahead jazz and the introduction of Groove Yard, his debut CD, two years ago. He also plays on two releases by the jazz outfit Seattle Groove lead by Deems Tsutagawa. In April, Leighton released Just Doin' Our Thang, a 12-cut CD featuring a Hammond B-3 organ trio behind Leighton's alto flute. And the group's interpretation of the theme from The Pink Panther might spark second thoughts on the original. Moore's chancy drum riffs; Bob Boss' off-key bursts of rhythm guitar; the legato values and color behind the theme: Leighton's treatment takes on a life of its own, eons removed from Henry Mancini's austere title entry from the 1963 movie of the same name. The collection also features the Gershwin staple “Summertime,” sung this evening by Cynthia Hammond. Hammond plays to the house as La Jolla's 40-somethings filter in to reciprocate; her trumpet voice holds their groove through Carrie Landsgaard's sultry “Chain of Fools” and DeNeille Thompson's indelible “Georgia on My Mind.” The future got into the act, too. Leighton protege Joyce Caci trilled through a nimble entry, finishing just before her ear-to-ear grin got the better of her. And through it all, there was the headliner, backstepping, pitching and leaning into a higher call. Those crazy Byzantines knew what they were doing when they invented the flute, all right. From a distance, the darn thing looks like a magic wand – the same one they've bequeathed to a gifted, unassuming young descendant who just can't seem to sit still. Now, that's jazz. Martin Jones Westlin is the theater critic for San Diego CityBeat newspaper and covers news and the arts for a number of San Diego-area publications.