FIRST OFF . . .

Britain’s Prince Charles and Princess Diana caught a London rock ‘n’ roll show together Saturday night, after weeks of speculation about the state of the royal marriage. Diana, appearing in a skin-tight, purple satin suit, munched sugary popcorn, clicked her fingers and drummed on her knees at the Wembley Stadium concert by Genesis while her husband, sitting next to her in the royal box, nodded his head in time to the beat and tapped on his knees during the faster songs. Proceeds from the benefit concert are earmarked for Charles’ charity for British youngsters, the Prince’s Trust.