Gotcha! Agree with all of your points, esp listening with lights dimmed. A tapestry is a better idea than an oil painting anyway, and you've also got me thinking about a really neat antique horse blanket I have, and now Navajo & Cherokee blankets and quilts too. The neat thing about a solution like that is how interchangeable it would be. But I understand that it's not likely to be a priority in a serious, dedicated listening room where the lights are low!
PS: I finally read your PF essay. Impressed by what you said at the end about classical music. I've always said that rock music sounds better at home than it does in a concert venue, while classical music always sounds better in the concert hall. You appear to be one person who has transcended that limitation. Salut