The near-full moon hovered above three massive outdoor screens. Thousands of people looked at the screens with anticipation. At strobe speed, each screen flashed drum skins, guitar frets, backlit Joshua trees and saguaros, and the faces of older men. Heart-pumping rhythm pounded through acres of speakers and shattered the desert air. Like LSD-fueled geysers, fireworks blasted millions of rainbow sparks into the dry, windless sky.