Can you remember instances of people he put in each cluster? I'd think Mozart would be a young master, and Beethoven an old genius.

I finally remembered this comment while at home and able to access the book. His name for the artisan category was "experimental," which makes more sense. Another distinction that I forgot to mention is that people tend to talk about the 'body of work' of experimentalists as important, but single works by conceptual artists stand out. If the same paintings show up in art books, then the artist is more likely to be conceptual; if every art book includes a piece by someone but they all pick different pieces, then the artist is more likely to be experimental.

Turns out he has a section on poets, and another on novelists. Among the 20th century poets, he lists Frost, Williams, Stevens, and Lowell as experimental, and Pound, Cummings, Plath, and Eliot as conceptual. For novelists, he lists Dickens, Henry James, Twain, and Woolf as experimental, and Fitzgerald, Hemingway, Joyce, and Melville as conceptual.

(He ranks Ulysses as more important as A Portrait of the Artist as a Young Man, which is itself more important than Finnegan's Wake.)