What bands or musicians were once enormously famous, and then seemed to have vanished off the face of the Earth? I'm not talking about One Hit Wonders like Los Del Rio, Nena, or Dexy's Midnight Runners. I'm not even talking about One Album Wonders like Hootie and the Blowfish, Huey Lewis and the News, or Lauryn Hill. I'm talking about bands or artists who were extremely popular for a decade or more, influencing tons of future artists, and then when their time in the spotlight passed, vanished, almost without a trace. Example 1: Nine Inch Nails. You never hear them on the radio anymore, even the oldies stations. You never hear anyone talk about them as influences, yet they were extremely influential during their time. And today's pop music is hugely influenced by the idea of sampling noises, bending and distorting them, and turning them into songs. Example 2: Sam Cooke. He has been called the "King of Soul". He was a huge influence on pretty much any soul singer who came after him. And while you may actually recognize a song of his or two, unless you grew up during his time, you probably don't know who sang them. When the general public, not of the era, mention the great soul singers of all time, his name is largely missing.