Musical Must-Reads?

Please educate me.

I’ve been playing bass for a while and I have a keyboard and acoustic guitar… Anyway, I’ve recently had somehwat of an epiphany when scales, chords and tones started fitting together logically. My teachers (yeah, I’m paying multiple now) suck at music theory. What I’d like is something larger (probably a book, thus the “must-reads” in the question) to study which might take me a little longer to master but doesn’t leave too many holes.