Woo-hoo! Thanks to possibly some initial miscommunication, then my inability to leave a nagging issue alone without constantly worrying at it, and then Tony-Wrangler-Of-The-Tech kindly patching my personal shortcomings, Book Zero now has a contents page you can click to jump straight to the song you want, and if your PDF reader shows bookmarks – which it does – all the songs show up there too.
It’s great. This is version 7. The cover has blue writing. If yours is different then it won’t support this sorcery.