"About three or four minutes into the conversation," May says, "I began to realize it."

Then the Allman Brothers guitarist popped the question: Would May try out for the band?

"I got real nervous all of a sudden," May confides. "And when I said yes, I tried not to sound too much like an anxious kid."

That once-in-a-lifetime offer came a few months ago, when May and his band, the Agitators, were in Betts's home base of Sarasota, Florida, playing a string of dates at a cozy Gulf Coast blues venue called the Five O'clock Club. May's swinging urban blues with a tart Texas twang -- coupled with his furious yet fundamentally refined command of the Telecaster -- have found a following in the Sunshine State. He also does fine in Houston, racking up glowing mentions in the local press, earning solid endorsements from fellow players and drawing consistent crowds at the Velvet Elvis and the Big Easy.

Still, May won't argue the point that his biggest breaks have come when he's skipped town. It just so happens that a regular May befriended at one of his periodic Sarasota gigs is Betts's golfing partner and turned him on to May's acclaimed 1995 debut CD, Call on the Blues. Quickly, word got back to May that he had a celebrity fan.

"[Betts] asked my friend, 'Who's that singing on there?' When he told him it was me, he said, 'Man, I thought that was a black guy,' " says May, whose chameleon-like vocals toy with the color barrier, fluctuating effortlessly between a salty redneck drawl and a silky R&B croon not unlike Robert Cray's.

In late February, Betts made an appearance at one of May's Sarasota shows and, duly impressed, invited him on the road as an opening act for a handful of dates on the Allman Brothers' summer '97 tour. It was those performances that May had assumed he'd be discussing when he received word one day to call Betts immediately. Instead, Betts offered May the audition.

"He was real nice about it," recalls May. "He starts talking to me about some problems they'd been having in the band [guitarist Warren Haynes and bassist Alan Woody recently left to focus on their side project, Gov't Mule]. He was saying things like, 'I'm not trying to break your band up; we only play in the summertime .... ' "

A month later, May was trading licks with Betts at his Sarasota home. "We jammed on everything from 'Hideaway' to 'Black Cat Bone' to Allman Brothers stuff to the Texas swing stuff that he likes," May recalls. (Betts couldn't be reached for comment, but Allman Brothers manager Bert Holman confirms the tryout.)

But alas, May didn't play enough slide to get the gig. Not that it mattered, really. The opportunity alone, May says, was enough to send him into fits of euphoria -- he was high for weeks. "It was quite an experience," May says, understandably tongue-tied when it comes to articulating the thrill. "Just to get that phone call, that's something that very few people get the chance to experience."

But then, the Columbus, Ohio, native has received more than his share of experience in the last few years, laying into it with Joe "Guitar" Hughes both live and in the studio and warming up stages for the likes of Anson Funderburgh, Smokin' Joe Kubek and Mason Ruffner. Not too shabby when you consider that it's been only about ten years since May first shifted his loyalties from rock and country to the blues. The transition came about quite smoothly, actually, with a technical ease that might make more conservative aficionados of the genre skeptical -- even a little jealous. "I almost feel guilty sometimes," he says.

At 35, May has paid fewer dues than some, but he has also paid attention to those best equipped to teach him a thing or two. Still, he's well aware that in a genre that tends to gauge a player's worth by the harshness of his life, he remains on the short end of the scale. And he'll likely spend another decade (at least) living down his middle-class Midwestern background, especially in a scene steeped in the Third Ward ghetto mythology of Houston blues bellwether Lightnin' Hopkins.

But May swears that, at this point, he's not interested in winning over the purists, so long as his heart's in the right place and his history is in order. On guitar, May boasts a barbed precision that recalls the late Albert Collins, the sort of full-on command of his instrument -- equal parts raw feel and technical polish -- that can't be fudged. Maybe that's why May has earned the respect of Hughes, a childhood friend of the Houston-bred Collins. Hughes even added his guitar expertise to that of May on Call on the Blues's instrumental tribute to Collins, "Hail to the Iceman."

As is hardly out of the ordinary for a younger player, May grazed the blues via Eric Clapton and Jimi Hendrix while growing up. But he didn't immerse himself into the form until he moved to Houston in 1982. And when he heard Collins, he was hooked for good.

"I was driving around with a friend of mine that had a copy of his live album," remembers May. "His attack was totally unique. It was true blues, but it had this distorted rock sound."

From that point on, May never wavered, abandoning all other distractions -- including the country and rock projects he was struggling with at the time -- and focusing on authenticating his blues chops. "Luckily I had a job at this music store down in Pearland," he says. "It was a slow store, and I'd sit around and practice. I wrote my whole first album there."

May was a quick study, and eventually he went from hosting marginal blues jams at a Clear Lake nightclub to headlining with his own band at the hipper Houston venues. By 1995, he'd recorded what would become Call on the Blues. It found a home not on a Texas label, but on the Memphis-based Icehouse Records, which is owned by Johnny Phillips, nephew of storied Sun Records producer Sam Phillips. May's upcoming sophomore outing, the considerably more guitar-heavy Telephone Road, is due out on Icehouse in July.

While May is beginning to find an audience in other parts of Texas (Fort Worth, in particular) to match his profile at home and in places such as Florida and Tennessee, notoriously fickle Austin has been slow to warm to the guitarist. But maybe that's no shock, given how provincial the Austin blues scene has become since Stevie Ray Vaughan died. Never mind that May is a quality blues picker with scads of soul; not only is he a non-Texan, he's from Ohio, of all places.

"If you can sound like [a] Vaughan, you've got it made there," May laughs. "Maybe I ought to try harder."

Mark May and the Agitators perform at 7 p.m. Thursday, June 5, at the Juneteenth Blues Festival at Miller Outdoor Theatre, Hermann Park, 100 Concert Drive. Free. For info, call 626-8000.