Downtown Phoenix music promotion has essentially been taken over by Live Nation. With its purchase of The Van Buren, the company has dominated the upper-tier indie-rock niche that was once the bread and butter of Charlie Levy’s Stateside Presents. But locally promoted live music is popping up in unexpected places, including the Showroom at Wild Horse Pass resort and casino in Chandler. Since Anastasia “A.P.” Palmer Johnson stepped in as the casino’s corporate director of...