Since the Bangles' heyday in the 1980s, singer Susanna Hoffs has added several bullets to her resume. The California native became a wife, mother and solo artist during the 1990s, and the new millennium found her reconvening with the Bangles for a critically heralded reunion album. Although she continued touring with the group, Miss Hoffs also launched a partnership with fellow songwriter Matthew Sweet, whose fanaticism for '60s pop music rivaled her own. Using Mr. Sweet's home recording studio, the duo began recording new versions of classic '60s songs. The material encouraged Miss Hoffs to buffer her melodies with dense...