Johnny Watson is yet another member of that remarkable generation of bluesmen who stormed out of Houston in the late 40s and early 50s, melding the smooth stylings of Texas guitar pioneer T-Bone Walker to the more aggressive sounds of R & B and, eventually, rock 'n' roll. Watson moved to California in the early 50s and worked with Chuck Higgins's Mellowtones as a pianist before signing on with the Modern label and adding "Guitar" to his name. In the early 60s he cut loose with such hits as "Cuttin' In" and "Mercy, Mercy, Mercy"--raw-edged testimonials to the nascent rock 'n' roll rebellion. In the 70s he played a major role in the development of blues-funk fusion. Though he achieved his greatest commercial success during this time--"A Real Mother For Ya," "Gangster of Love," "Love Jones"--he was hindered by changing popular tastes and rumors of personal unreliability. Older and wiser--but no less full of fire--Watson has returned to the blues/R & B scene on the Bellmark label, owned by famed soul impresario Al Bell. His musical vision is as uncompromising as ever, and he sounds ready to take on the world again. Also on the bill are Little Milton, Clarence Carter, and Bobby "Blue" Bland. Saturday, 8 PM, Arie Crown Theatre, McCormick Place, 2300 S. Lake Shore Dr.; 791-6190 or 559-1212.