There are two kinds of technical writers: the ones who like to create indexes and the ones who think indexing is the most boring and horrible work imaginable.
I myself like indexing. During my first few months as a technical writer, I even indexed a new book for a more experienced writer who was working against a deadline and didn't much like indexing. One of the minor frustrations of my otherwise-excellent new gig is that we use Dreamweaver, which is a website-design tool. It's not a good technical-writing tool, among other reasons because it has no way to create and maintain indexes other than by hand. I created my very first index by hand, for a manual documenting the Well's extract command. It was a good exercise, but not something I'd want to do for a longer document. Real technical-writing tools, such as FrameMaker and Epic, provide a way to place an index marker and the entry in the running text, then generate the index itself.
So....Alex's index runs from Abbado to Zweig. Were index cards involved? A hired indexer? (Yes, there is a such a profession!) Microsoft Word?