The status of the cover song has shape-shifted throughout pop-music history. Well into the 1950s, it barely even needed a name: It was just the routine way of doing business. During the rock era, covers became suspect as inauthentic, the stuff of the hack bar band, unless an artist “made the song their own.” With the rise of hip-hop, covers were displaced by sampling and remixes, but then samples themselves became more concealed and layered, for reasons of both art and copyright. In the 2000s and earlier this decade, the practice migrated to YouTube, where concert clips or home videos of one-off covers, rearrangements, and parodies might show off the skills and wit of amateurs and pros alike but still seldom troubled the charts—unless they also made it to soundtracks or TV ads, where acoustic remakes of once-upon-a-time hits (either twee or glum or both) have become a staple.