This album is Mastered for iTunes. For Kisses on the Bottom, Paul McCartney dips into the same songbook of 20th-century standards he’s so generously contributed to as a songwriter and a Beatle. With guest contributions from Eric Clapton and Stevie Wonder and backing by jazz vocalist/pianist Diana Krall and her band, he interprets favorites from his youth popularized by the likes of Fats Waller (“I’m Gonna Sit Right Down and Write Myself a Letter”), Nat King Cole (“It’s Only a Paper Moon”), and Frank Sinatra (“My One and Only Love,” one of two bonus tracks).