Whatever happened to the primetime music performance?

[TheDreamMaster]

I mean something specifically by the thread title. It was really common in the 50's, with the controversial performances of Elvis being a big example, but what ever happened to their being a big draw to having musical performances as a primetime event on television? I know you can occasionally catch live performances or recordings of on HBO or order them via Pay-per-View/On Demand, but why did these fade out of our culture? I know I'd never want another one of those Sonny and Cher/ Brady Bunch variety shows again, but actual televised concerts. What changed so much that these never seem to happen anymore? Was it because shows like Leno and Conan get a music artist per night, but even so, they usually only get one song. I don't expect Marylin Manson or Snoop Dog, or anyone else in this day to try to appeal to a "family-friendly" audience, but it just intrigues me that this kind of thing was big at a time, and faded away quickly it seems.