Bb Jazz Blues? ...
working my way through this lesson. got the full rhythm, the triad rhythm and the basic triad arpeggio parts down relatively well. (will work on the lead part soon.)
my question is on the full chord parts. I don't have much formal theory training, but have played these chords before. However I've never really understood why the Bb7 is played as Bb13 then Bb7 then Bb6. I hear the differences and they all sound great, but what makes the Bb13 the choice over the 1st couple bars. then the Bb6 over the middle change? Is it just taste?
hope this doesn't sound like a dumb question.
my question is on the full chord parts. I don't have much formal theory training, but have played these chords before. However I've never really understood why the Bb7 is played as Bb13 then Bb7 then Bb6. I hear the differences and they all sound great, but what makes the Bb13 the choice over the 1st couple bars. then the Bb6 over the middle change? Is it just taste?
hope this doesn't sound like a dumb question.

Comments
Hope this helps and happy playing!
Your playing a Bb7. In order to add a little variety you can add color tones. The 1,3,5, and 7th degree of the chords are the essential tones, but you are free to add extra tones (like the 13th). At its core you are still playing just a Bb7 chord and I would mentally classify it as such while playing.
It is a matter of taste and a good tactic to spice things up. Its common to add the 9th and 13th.
I tend to not consider this a chord substitution, but a quality change.
I'll let you know how I progress.
thanks!!!!
loving this lesson.