“This is a secret show, right?” said Mayer Hawthorne at the start of his performance at the opulent Grand Ballroom of the Park Plaza Hotel in Los Angeles. “Well, tonight, the secret word is fun.” He kept his word as he and his nimble band, The County, blazed through two dozen songs in his updated classic soul style, infused with everything from doo-wop to hip-hop. Over the course of the evening, Hawthorne and his band thrilled the crowd with a set featuring selections from Hawthorne’s acclaimed album, How Do You Do, plus such fan favorites as “Green Eyed Love.”