Teachout's biography of Duke Ellington still leaves many questions unanswered at least for me, but it is a good overview of what Ellington did in his career. Well, most of what he did was touring with his constantly churning, frequently dysfunctional, often brilliant and sometimes lackluster band.
I am of course interested in his psychology as a person who was simultaneously irresistible and unknowable, but unfortunately Teachout didn't provide a lot of analysis (speculation?) in this area. Every couple of chapters Teachout would gripe about how Ellington stole credit for music written by his band members (including an entire chapter about how Billy Strayhorn was wronged by not only Duke but also critics and historians) or how he mistreated women in his life. He does not, however, provide any explanation on why Ellington was able to do these things without losing their attachment to him.
For example, one could argue that Strayhorn remained in Duke's shadow because of his lack of marketability as a homosexual, but by all account Strayhorn did not act as if he was ashamed of his sexuality and never pretended to be straight. He could have stayed in others' shadows if he were so inclined. Why did he stick with Duke's band for most of his life and watch Duke take credit for his own work? Why did many others in the band? Band members trickled (or stormed) in and out over the five decades, some left in a rage and struck out on their own. Some came back. (Johnny Hodges was an example of success in both places.) I can believe that Strayhorn grew to resent Duke's credit-hogging of his work, but he nevertheless drifted back into Duke's fold until his (Strayhorn's) death. They were jazz musicians for god's sake, by nature and definition unabashed individualists. They are notoriously harder to herd than cats!
The same with women. It's not like Ellington's major long-term relationships were with weak, submissive women. His first love and only wife slashed his face with a razor. Another of his long-term partner Evie had a fiery temper. None of them seemed like spineless voiceless victims. Every few chapters, Teachout would indignantly remind the reader that Ellington refused to give the title of Mrs. Ellginton to women in his life. Yet most of them did not leave him. Why? What was his pull? Ellington spent lavishly on his friends and family, so much so that he was deep in debt at the time of death. But money alone cannot explain his hold on people around him.
One thing in Duke's personality that did come through in the biography is his intense fear of being alone and his actual loneliness. He needed the band and could not live without it, but this busyness never provided the relief from the loneliness.
Another thing that came through, without heavy-handed treatment, is the scars of racism that all American jazz musicians have to live with. And yes, the white ones too.
Not being a musically knowledgeable person or a connoisseur of Ellington's discography, I am not able to assess Teachout's critique of Duke's music. It seems that Ellington's innate sensibility as a visual artist --- he showed a lot of talent in art before he got into music --- gave a strong impressionistic character of his music. Teachout does not, however, comment on the sensuality and sexuality that are evoked bluntly, almost nakedly, in some of his pieces.
