Long have I known the truth about artists' longevity and career viability. I was a mere pup when I formulated this theory, as a result of the cauldron of artistic shit that was the 1980s.
Once you see an artist start to dress up on stage, in suits and other slick civvies (they're almost always black clothes), as well as their band, their artistic integrity and their nowness is done. Done.
Most obvious victims: Elton John. Billy Joel. Eric Clapton. Rod Stewart. Many more.
The stage is dark, with slick lighting emphasizing the slick dress-up clothes that adult boys get to wear. It totally takes away from the music. The music becomes static; it becomes a mockery of past glory to even perform it. Black clothes suck the life out of once-great artists.
The ones who are still great, still turning out alive performances and recordings, dress the way they dress. They're not trying to impress anyone. Petty. Springsteen. CSNY. Done, as my brother says.