Leroy talked about the jazz side and blues side. He describes some of his first experiences with real 'outlaw' jazz as he called it.
This is an excerpt from Leroy Cooper's memoir as told to me back in 2007. The material is copyrighted by Susan Cross and cannot be copied, published or duplicated without permission.
"My first automobile I got when I was playing with Frankie Lee Sims. And I didn’t know that he was a big man. So I got down on him. Then I heard these guitar players talking about Frankie Lee Sims. I said he was just another cat to me. I never did know what the story was and when to stop. He’d say, “Blow.” And I’d go voom, voom, voom. And I said to myself, when do you stop? And finally when you got tired of blowing, he’d get back to singing. No charts, no nothing. Just blow.
That’s the way it was with Sun Ra, too. I used to rehearse with Sun Ra in Chicago. And that’s the way he’d come to me.
He’d say, “Play.” The cats in the band would look at you and say, “Play. Just play your instrument.”
That’s not easy to do. He would call me changes. Sun Ra might get a bell. Creativity. People was sitting there so high they don’t even know what day it is. I didn’t last with that too long. I got friends that loved them. They stayed with Sun Ra for years. I’d see them in New York and they’d say come down to the so-and-so and I’d say, I’ll be there. But I didn’t want to go to that.
This is just a snippet. There's much more about Count Basie, Duke Ellington, etc. who he considered more traditional because they used charts and books.