I just read a small section and was totally impressed by Rule's description of what it's actually like to sing - sing properly, not howling, screaming, or pop singing like I've read in other books I won't mention.
Singing well is difficult and requires training, and Rule really nailed what it's like, the thought process as you're singing, all the technique. I was so impressed I thought to myself, Rule's gotta be a singer.
Lo and behold, she's a vocalist with the Boston Symphony Orchestra/Boston Pops and has a BA in Voice. It totally shows, this is awesome. It's so nice to read a book that involved actual technique, not just 'i opened my mouth and sang it was pretty/awesome despite my no training.'