John Doe has mastered the much-overlooked art of writing and performing songs that celebrate life’s sweetness without lapsing into greeting-card sentiment. From the opening surge of “Don’t Forget How Much I Love You,” Doe proves an artist doesn’t have to be in pain to deliver the goods. His backing group features Smokey Hormel, Don Was and Giant Sand’s Howe Gelb among the all-star cast, while guests — Patty Griffin, Jill Sobule, Cindy Wasserman — spice up a few tracks. Doe has always loved classic rock ‘n’ roll. His band X paid tribute to rock’s origins and tracks here like “Never Enough,” “Jump Into My Arms” and “Handsome Devil” intuitively observe rock ‘n’ roll history while still putting Doe’s unmistakable mark on everything he sings. He’s no slouch on ballads either. “Little Tiger” and “Sweetheart” are stripped-down songs that make for bedside lullabies. Keeper is a great, unforced collection of tunes that are as timeless as they are current.