I have a soft spot for hard rock. So I find myself in one of Austin’s live music clubs listening to a band on the tail end of their world tour.A guitarist is under the stage lights at Come and Take It Live, swaying and concentrating, the strains of a Stevie Ray Vaughan classic floating from the amps. The night air crackles. The rapt audience takes it in, applauding as the guitarist moves gracefully through the soulful notes. If you’ve played a musical instrument of any kind at any skill level, the live show reveals the human effort at the foundation of every good performer, performance and son...