Airs Friday, August 30 at 11 p.m. In the beginning—there were no beards—nor fuzzy guitars. After more than 4 decades, ZZ Top‘s Billy Gibbons gets set to revive the seminal Moving Sidewalks. Also, in the wake of the Newtown school shootings, NPR Music critic Ann Powers explores about the healing force of a Natalie Maines recording. Plus, Iron and Wine caught live in Studio 1A , on the next edition of Texas Music Matters.