Watch the Harmonic Analysis online guitar lesson by Brad Carlton from Guitar Lab: The Imaj7 IVm6 Progression
In this video, I'll explain the harmonic analysis for these two different chords in depth:
The Imaj7 (Bbmaj7) could function as the I chord in the key of Bb or as the IV chord in the key of F. Throughout this course, we'll treat it as a I chord.
The IVm6 (Ebm6) could function as a Im6 in Eb melodic minor or as a IIm6 in Db. Throughout this course, we'll treat it as the Im6 in Eb melodic minor.
We are choosing this harmonic analysis because it offers up a D common tone between the Bb major scale and the Eb melodic minor scale. Be sure to examine Charts 1 through 5 and take the time to memorize the spellings of all chords and scales that you'll need to play.