The Four Seasons and the Beach Boys were virtually the only American groups whose successful careers were not derailed when the Beatles and the British Invasion bands hit the States in 1964. In fact, 1964 ranks as the Four Seasons' biggest year of all, despite the insurgency from abroad, which attests to their durability and appeal among America's teenagers. That appeal stemmed from the Four Seasons' ability to complement spotless Italian-American doo-wop harmonies with the forceful falsetto and three-octave range of lead vocalist Frankie Valli, superb songwriting from group member Bob Gaudio, and arrangements and production that drew upon everything from Phil Spector's "Wall of Sound" to the danceable beat of Motown's pop/R&B singles. During a hit-making streak that spanned the years 1962-68, the Four Seasons netted two dozen Top Forty singles, including the Number One hits "Sherry," "Big Girls Don't Cry," "Walk Like a Man" and "Rag Doll." They've sold over 100 million records worldwide, making them the most successful white doo-wop group in rock and roll history.