No sound better crystallizes the promise and euphoria of the ‘60s than the bright, ringing Rickenbacker chords that powered so many Beatles and Byrds hits. But as the sound was overtaken by hard rock in the ‘70s, torch-bearing underdogs like Big Star and Flamin’ Groovies infused that joyous jangle with a more melancholic edge, as if to signify the passing of pop’s golden age. Since then, the equally elating and aching sound of jangle pop has been embraced by successive generations of melody-making misfits, filtering into the erudite college rock of R.E.M., the post-grunge bubble gum of Teenage Fanclub, and the dreamy indie of Real Estate.