HENRY DILTZ, THE OFFICIAL PHOTOGRAPHER FOR THE 1969 WOODSTOCK MUSIC & Art Fair, was sleeping behind the stage in his station wagon on the morning of Aug. 18 when he heard the music crank up. He roused himself and hustled to the stage to capture on film the festival’s final performer. By the time Jimi Hendrix went on, at 9 a.m., the once half-million-strong audience had dwindled to about 25,000. “There were these huge speakers,” Diltz says. “Now that there wasn’t a crowd to absorb the sound, it bounced off the surrounding hills.” Diltz recalls his amazement when he heard Hendrix’s incandescent rendition of the U.S. national anthem. “It was very eerie in that stillness to hear this single guitar playing ‘The Star Spangled Banner’ so loud,” he says. “You just thought, ‘Yeah, we own that too. That song applies to all those half-naked wet hippies standing in the mud.’” Hendrix passed away on Sept. 18, 1970, at age 27.