Buddy Guy has cut a swath through popular music with his Chicago blues sound, influencing everyone from Jimi Hendrix to Stevie Ray Vaughn. He is ranked 30th in Rolling Stone magazine's "100 Greatest Guitarists of All Time." To understand why, see him at the Clay Center in a show starting at 7:30 p.m. Sunday.The bill also features young, award-winning American blues, gospel and rock singer-songwriter Jonny Lang. Tickets are $30, $45, $55 and $75. Call 304-561-3570 or visit www.theclaycenter.org.