The raw immediacy of the blues is best captured live, as Texas guitarist and contemporary bluesman Gary Clark Jr. is well aware. Two of his four major label albums have been live ones, including Live/North America 2016, and Clark unleashes his true, unbridled character on stage: His prodigious guitar work (compared to Hendrix and Stevie Ray Vaughan) bucks, twitches, and screams in spirited eloquence, often reflecting the anguish of struggling characters. His singing probes new layers of expression too, particularly unveiling its deeply soulful component, and he increasingly favors a falsetto that invokes both Curtis Mayfield and Al Green. Even the elements of soul, gospel, funk, R&B, and hip-hop that set Clark’s 21st-century blues on a more progressive path acquire fresh nuance. Austin blues singer/guitarist Jackie Venson opens.