Comment by zozbot234

One can argue whether Tymoczko's approach genuinely leads to understanding theory "from the ground up". His research is best understood IMHO as a worthwhile (in itself) "tweak" and generalization of a previous theoretical approach known as "Neo-Riemannian theory", named after Hugo Riemann's descriptions of tonal harmony (i.e. the general working of 'chords', or rather, major and minor triads). Seen from that POV, it's quite helpful. As a general description of what might go on in a piece of music (even "classical" music)? Maybe not so much.