Drift off with Beach House, Cocteau Twins, Grouper, the Pains of Being Pure at Heart, and more With many of the lists we’ve assembled over the past few years, the parameters have been clear. To be considered Britpop, for example, a record had to be guitar-based, from the UK, and released during a certain period. We can argue endlessly about what’s a mixtape and what’s an album, but in assembling t