Anything can happen when Narada Michael Walden throws on his Santa cap. The Grammy-winning producer and drummer’s annual holiday benefit concert — “A Rockin’ Christmas Shindig Hullabaloo,” if you prefer — takes place at the Throckmorton Theatre in Mill Valley on Saturday, Dec. 16, and promises a variety of treats. This year’s guests include Ronnie Spector and the Ronettes, who gave a handful of seasonal standards a girl-group makeover on Phil Spector’s classic “A Christmas Gift for You” album. Proceeds from the concert go to the Narada Michael Walden Foundation, a nonprofit organization dedicated to supporting music appreciation and education for children in the Bay Area.