Four days before his 68th birthday, Eric Clapton arrives in St. Augustine, celebrating half-a-century as a professional musician. As a 16-time Grammy winner and the only three-time inductee in the Rock & Roll Hall of Fame (solo artist, member of The Yardbirds and Cream), this guitar hero has nothing to prove. Earlier this month, Slowhand released his 20th studio album, “Old Sock,” which has an “endearingly breezy spirit,” according to USA Today. The Wallflowers, Grammy-winning rockers in their own right, open. 7:30 p.m. March 26, Veterans Memorial Arena, 300 Randolph Blvd., Downtown, $34-$96, 630-3900, 1-800-745-3000, livenation.com, jaxevents.com.