Sweet child o'mine has this progression in the intro: Db (sus4)-Db-Db(sus4)-Db-Ebm11/Cb-Gb (add2)-Db (sus4)-Db-Db(sus4)-Db
And this progression in the verse: Db-Cb-Gb-Db
How would you explain this progression (I-VIIb-IV)? The intro and verse has this same progression but differ in one place. The intro has Ebm11/Cb. How would you explain this chord? Should this progression be explained with classical music theory or with more modern music theory? I remember a teacher saying that classical music is sometimes based on moving chords in thirds or sonething similar rather than being based on I-IV-V-I. Does this apply to this song/tune?