He was born in Shreveport as one of four sons of Byrum Teekell, an insurance executive, and Jan Gray Teekell, formerly of Minden. They married August of 1950. Music seemed to have captivated Hassell, even as a young child. His mother, who played piano, noticed her son pressing the keys to make chords. Eventually, he learned to play before taking music lessons and learning to read music. "I found it really tedious and it was pretty much a disaster," he recalls of lessons. "I quit and I didn't play for several years after that. But I took it up in my teenage years," he adds. He took more lessons in his senior year in high school, mainly because "I could get credit for it and therefore not have to go to school as much." His teacher was Robert Buckner, "a beautiful man," and "a very, very accomplished music professor at Centenary". Meanwhile, the Teekell family lived near Arthur Ferrante, of the pianist duo, Ferrante and Teicher. "A few times I'd gone over there and he let me watch and he made me play for him one time which was really embarrassing," he recalls. In 1975 at age 15 he began playing clubs as the youngest member of a four-piece band, Faust. The group played Top 40 music on Bossier Strip, at EM Clubs and Officers' Clubs, and in places "on Commerce down in Shreve Square." About a year later he joined the Otis Wheat Band, a country rock group, as a keyboard player. By the time he graduated from Captain Shreve High School in 1977 he was working steadily as a musician. He recalls making about "twenty-two hundred bucks for three nights, and that was in 1978 and that was a lot of money," he recalls. Meanwhile, Hassell was recording in Shreveport, including two records with Southpaw. He recorded at a Sound City, a studio on Line Avenue owned by Stuart Madison and George Clinton. Once, he played for Pot Liquor (also written as Potliquor), a "Louisiana legend band that had been around since the `60s." Hassell graduated from Full Sail Recording Institute in Orlando, Florida, then lived in Albuquerque, New Mexico and Dallas for several years where he ran a remote recording service. He recorded live concerts with equipment on a 40-foot bobtail truck with a 48-track studio. He also teamed with Paul Christensen in Omega Audio, and with a remote recording truck, worked shows starring talent from "Pat Boone to Prince." Such engineering experience, helped him when he moved to Nashville in the mid-1980s. There he played for a Reba McIntire tour and worked for Kix Brooks before the highly successful duo, Brooks & Dunn, was formed. Hassell played in the band for Billy Ray Cyrus when Achy Breaky Heart soared on the charts. He became accustomed to touring by bus, and slept "like a rock. I never had a problem. I'd have problems when I'd get off the road when my bed wouldn't be moving," he recalls. Hassell spent 28 years in Nashville recording and traveling with shows. His longest extent was playing for Mark Collie for "eight or ten years." He worked with so many recording artists that "it would be a shorter list of who I didn't play for." He formed an all-Louisiana "side band" called The Bayou Degradables, with Luther Kent of New Orleans as vocalist. Hassell returned to Shreveport and became involved with movie production for StageWorks of Louisiana. He also owns a music publishing company where he occasionally plays sessions. He continues to live in Shreveport with his wife, Suzy Boyd Teekell.