The other evening at the Red Rock open mic I was talking to Bill, a singer with an incredible voice. He referred to Bob Dylan and mentioned "Selling Out".
I noted that the concept of "Selling Out" was hard to apply to Dylan, since he had a record contract within weeks of hitting NYC, before he wrote any of his most innovative songs. The question of "selling out" was around in the '60s and '70's, but its application has always been problematic.
Some artists create a space that is difficult for viewers or listeners to navigate. If that difficulty isn't too great (the level differs with different people and different media) people can be attracted to playing with the space, learning how to navigate it, and how its edges are determined. The attractiveness, as I've written before, is a function of Vygotsky's "zone of proximal development".
With the mass media that was present in the '60s, large numbers of people shared the same inputs, and pop artists emerged, like Dylan.
What happens, I believe, is that people eventually learn to navigate the artist's space. Artists also either exhaust it, or move to other spaces for their own explorations. The artist can lose the ability to create an attractive zone. Some artists find strategies that work throughout their whole lives, like Duchamp, Picasso, Zappa. Others have the space lose its foreignness for much of its audience--people domesticate it.
I like Beefheart's "selling out". After putting out some incredible sonic constructions, he put out an album called "Unconditionally Guarenteed" with a photo of himself holding handfulls of cash. The music inside was simple and dull, I've never heard anyone defend it. So when Beefheart sold out--explicitly--he lost his audience. Some sell-out. He later put out a couple of killer albums, after regrouping. And the space was back.
As an artist, you find a space to manipulate. Depending on the strategy of that manipulation, and the complexity it engenders, it may give you enough to work with for your whole life. Or you may work through it within a year, and never find another. But the relationship of the artist to that space is not one of money. You can't buy it, and you can't starve yourself into it.