The story’s thesis and details have been well worked over since it was published. The Future of Music Coalition, an advocacy group for musicians, posted a long response on its site. The article’s author, Steven Johnson, responded in detail, and the group then answered him. The Times’s standards department considered a request for correction and decided against it. “We looked at it thoroughly and did not find a correctable error,” Greg Brock, senior editor for standards, told me. In my view, the original article should have clearly explained how the category had changed.