Dallas has been added to Van Halen's latest tour - and today's show won't cost fans a cent. Lead singer Sammy Hagar is keeping a promise he made in 1988 when he stopped a concert at the Cotton Bowl to apologize, saying his voice was weak because of a sinus infection and strep throat. "Like a fool, I said, 'I'll do a free concert for you folks,'" Hagar recalled. The show was scheduled in the afternoon at West End Marketplace in Dallas, TX on December 4th, 1991 with an estimated 80,000 fans in att...