"The 'jazz yodeler' is the most publicized aspect of my 'style,' " says singer Leon Thomas, "but if you check the record, I've done blues with Basie, rock-jazz with Santana, jazz with Archie Shepp and Pharaoh Sanders. That's why I call my group Full Circle. I sing it all, including opera.

"I just did a European tour with Jimmy Witherspoon, singing primarily the blues," adds Thomas, who will perform at Kilimanjaro's Heritage Hall on Thursday with Malachi Thompson's Free Bop Band. "You haven't heard all the things that Leon can do. The yodeling helped establish me and gave me my own little niche, but it's not the width and breadth of my talent."

Back in East St. Louis, those who knew the tall, rugged Thomas originally predicted he would make his reputation in sports. He was a star athlete in high school, with singing a passion, not a potential vocation. In fact, his entry into the music business was made in a baseball uniform.

"I'd gone into this club to buy some Cokes and [guitarist] Grant Green was on the bandstand with [percussionist] Armando Peraza." Thomas ended up on stage bashing the bongos -- without great distinction -- and his friends said, "You can't beat him playing bongos, but you can beat him singing."

"They told me to come back next week," Thomas recalls. "That might have been a brushoff to them, but it was an invitation to me, so I returned and sat around all evening until they let me sing. At about the same time, a St. Louis deejay who had heard about the jams on my side of the river came over and invited the band -- including 'the singer' -- to a live broadcast. And [at 16] I became a fixture on the show and hung up my baseball uniform. It's storybook stuff, but it's the way it happened."

Thomas' early endeavors in trying to expand the capacities of the human voice ("I always had the potential to make sounds but I didn't know what the heck I was going to do with it") were rooted in his listening experiences. "The blessing was being in the Midwest," he explains. "I heard everything -- blues, ballads, C&W, and certainly the jazz. It was never just one thing I wanted to do. I realized the voice was an evocative instrument. From the a cappella choir, I knew what pitch and tone value were. I knew singing was sustaining of notes, harmony and rhythm content, so I approached it from all angles at once."

Which is how he started to yodel. "I've always been able to yodel, from listening to Roy Acuff and Rex Allen as a child. But you don't want to be square. I've still got it in my mind to do a true country and western album and do some real yodeling. It's there, it's innate. Anything with my voice that challenges me, I'd like to try it."

As he reached into himself for spirits known and unknown, Thomas found himself moving in the same direction as John Coltrane on saxophone, evidenced in scat singing that was both faster and more fluid than the norm. "I was doing it before I ever heard him," he says. "My brother used to tease me that nobody else was playing like that. He said, 'Trane is doing all that fast jumbled up stuff like you.' "

He finally got to hear Coltrane when St. Louis' "most prominent ambassador," Miles Davis, brought his seminal quintet through. Actually, Thomas was more impressed with the group's tremendous bassist Paul Chambers, "due to his youthful age 19 in such fast surroundings. He was one of a kind. He was just a year older than I was, and he gave me inspiration that eventually I could make it in that small town of East St. Louis."

Still in his teens, Thomas started putting in his time with various local musicians (Oliver Nelson before the Octet, George Hudson's band when its pianist Ahmad Jamal was still known as Fritzy Jones). He ended up at Tennessee State University around the same time as Hank Crawford, Waymon Reed, Cleveland Eaton and Washingtonian Andrew White III, the world's foremost Coltrane scholar (he's annotated all his solos).

One visitor to the Tennessee State campus was Count Basie. Thomas sat in, and several years later, when Joe Williams left the band, he stepped into the featured vocalist spot. "You know, there are really two books in that band, a bass clef book left by Joe Williams and the tenor book left by Jimmy Rushing. With my range I sang both of them, and in my absence during Army service they really had a lot of problems. When I came back it returned to the single singer again, luckily for me."

Thomas stayed with Basie for three years in the mid-'60s, then embarked on a career that has included a long collaboration with Pharoah Sanders and the devlopment of his own group, Full Circle. He also spent 13 months as Santana's lead singer in the early '70s, once again doing two books, current material and "the stuff he was required to do live like 'Black Magic Woman.' Carlos Santana was reaching for a new audience, trying to get away from the acid-rock image, and spirituality was uppermost" in his music. Thomas' words for Sanders' haunting "The Creator Has a Master Plan" held true here. His entry into Santana was "that mystical person," percussionist Armando Peraza, who'd been at the St. Louis club at the beginning.