A mainstay of the Austin blues scene since the mid-'50s, W.C. Clark was hounded by a young Stevie Ray Vaughan to join his fledgling group (the Triple Threat Revue), and he co-wrote SRV's hit "Cold Shot." But W.C. Clark -- the oft-described godfather of Austin blues -- is usually left out of any list of Texas blues greats. Maybe it's a lack of flamboyancy or critical fawning; whatever the reason, the singer-guitarist's yeoman efforts are certainly worthy of greater acknowledgment. Clark's foundation is in the blues, but his sound also offers a heaping helping of the Stax-y soul that he was undoubtedly exposed to while serving his stint as shouter Joe Tex's guitarist. His new CD, Deep in the Heart (Alligator), veers from ballads to ball busters, and the A-listers backing him (including the Texas Horns) support rather than overwhelm him.