good read for very beginners, thats coming from someone who is still generally new to theory. Didnt get any new info from it, mostly good for song analysis. Would have liked to see a full chord library or even 7th and 9th chords explained more. There are more types of them producers should be aware of. Also understanding dominants/ passing tones/ leading tones, etc.. really helps beginners understand HOW to write a melody, don't remember it being touched on in there.
But for a free book its a good, interesting read. Would be disappointed if i paid, no offense. Just being honest. Only saying that because I am under the impression you will be selling it eventually.