As a self-conscious aesthetic, lo-fi didn’t come into its own until after punk’s pro-amateur, DIY attitude had already laid waste to popular notions of what constituted acceptable musicianship and recording techniques. Yet the idea of turning crappy sound into pure sonic gold reaches back to the classic rock era. The obvious precursors are The Velvet Underground and garage-psych bands like 13th Floor Elevators, who in the mid ’60s achieved sonic delirium through intentionally muddy primitivism. Around the same time, the post-Pet Sounds Beach Boys pretty much invented the concept of the warm and woozy bedroom recording, while The Beatles, during their “White Album” sessions, incorporated home demo-style graininess and feedback into their previously pristine pop. The Stones deserve a lot of credit, too. After all, there are entire stretches of 1972’s Exile on Main St. that sound like moldy-ass basement recordings.