Hi guys i have just finished watching the videos on chapter 3 of the "blues course one" and i understand the concept behind the dominant VII chords but i cant understand the flat 6th and 7th chords that he put into the progressions. I was having a look at the minor scales in the key i was playing and it sort of made sense that the flat 6th and 7th had the 6th and 7th note of the scale in them but it wasnt always the route note of the chord so i dont really get how the chords relate to the scales im not saying that they sounded bad they didnt i just dont understand it. I love playing nice sounding stuff but i also want to have a full understanding of the method behind it as well. Any help would be greatly appreciated.

Adam