Ian McGlagan The Faces

Since the mid-1960s, when his Hammond organ provided the British Mod band the Small Faces with much of its soul and swagger, keyboardist Ian McLagan has backed some of the biggest acts—and egos—in the business. Inducted into the Rock and Roll Hall of Fame in 2012 with another band, the Faces, he toured the world with Rod Stewart, the Rolling Stones and Bob Dylan. Artists from Chuck Berry and Bruce Springsteen to Bonnie Raitt and Paul Westerberg have called on him to punch up their sound in recording sessions and on tours. He hung out with Keith Moon and Pete Townshend of the Who. In 1998 he published "All the Rage: A Riotous Romp Through Rock & Roll History," an often hilarious, sometimes tragic sex-and-drugs tell-all—now out of print. Mr. McLagen, 69 years old, makes his home near Austin, Texas. "Mac" keeps his Hammond organ in a van outside his home, ready for club dates. His ninth solo album, "United States," is due out Tuesday (YepRoc). "It's not really about America at all," he says of the album. "It's about relationships."