How can I learn about the relationships between chords to build chords progressions?
Every book I read explains how to build chords, but they don't teach how to put the chords in progression. They just teach you some common chords progressions like I-V-IV, but they don't teach the "why" of this progression.
Let's say I have a Bb7/G# chord. How can I know the next chord that would fit in the progression and why this chord?
In particular the chord progression is:
Bb7/G# Gm6 Ebmmaj7/F# Bb
These chords are from the song "Aguas de Marzo" by Tom Jobim. They are very weirds chords to me. If I play the chord Bb7/G# alone it sounds very dissonant. But play the fours chords following the rythming of the song and it sounds beatiful.
What is the area of music theory who study the "why" of this, and not only the "how", which is what I have read in every book of "chord theory" for guitar. Any book you would recommend?