SAN DIEGO — What are the chances? On Wednesday night, 2022 triple-Grammy Award-winner Olivia Rodrigo performed at a bayside concert venue in San Diego with her band at exactly the same time Debbie Harry and her band, Blondie, appeared at another bayside venue here a few miles away. Both concerts were quick sellouts. Rodrigo drew 8,500 adoring fans to her gig at The Rady Shell at Jacobs Park, while Harry drew 1,450 devotees to Blondie’s gig at Humphreys Concerts by the Bay. Had any music fan been able to attend both events at once, it would have been doubly instructive. (This reviewer opted for…