It was a long, arduous day, full of intense sunlight and fine waves of dust that seemed to settle on everything and everybody. Still, vast numbers of young people (possibly 30,000) crowded onto the field and into the stands at Jeppesen Stadium Sunday for an all-afternoon rock concert featuring Pablo Cruise, Santana, The Marshall Tucker Band, and the Doobie Brothers. The fans fought the sun with thousands of soft drinks, long-billed caps and even an improvised rubber-hose shower. But in the end, the only thing that really soothed the sunburn was the music itself. April 23, 1976.