Legendary crooner Frankie Valli is playing San Antonio's Tobin Center later this month amid a social-media maelstrom. The Four Seasons leader's Oct. 26 concert in the Alamo City comes as recent viral concert videos prompt concern among fans about his fitness to perform. Some of those clips show Valli barely moving his lips, holding his microphone far below his mouth, prompting online speculation that he's lip synching.