Any suspicions that ABBA were a Eurovision-spawned flash in the pan were dispelled by the international success of their self-titled third album, released in 1975. This masterful batch of tunes further refine the Swedish quartet’s luminous vocal harmony-centered sound. In the States, the album is best known for its Top 40 singles “SOS” (pronounced by no less than Pete Townshend as “the best pop song ever written”), “I Do, I Do, I Do, I Do, I Do” (a soaring rock ballad with big-band overtones), and “Mamma Mia” (later the title number of an immensely popular Broadway musical). “Bang-A-Boomerang”—a hit in several European countries—also ranks among the key tracks here. There’s hardly a speck of filler on the rest of the album, which embraces everything from sunny reggae grooves (“Tropical Loveland”), hard-thumping glam rock (“Hey, Hey Helen,” “Rock Me”), and ambitious classically influenced instrumentals (“Intermezzo No. 1”). Overall, Björn, Benny, Agnetha, and Frida infuse every curvaceous melodic turn and brassy chorus hook with a joie de vivre that’s positively infectious.