Tone
As I get started on Blues for Big Nate. you comment on the 1-2-3 draw chord in the opening lick and about dropping the tongue and opening the throat (and I have heard you say this before). That is the first time I have actually heard the difference - WOW!!!!
OK with an open mouth but as soon as I put my tongue back on the harp and try to get that same difference I just can't seem to drop the back of my tongue while the front is on the harp - ????? Another just keep at it and it will eventually come??? Or is it more subtle and just work on keeping the throat open or ..........???
Another thing that works for me is to put the harp well in your mouth. If you hold the harp further back and leave real estate to really stick it in your mouth it's easier to drop the jaw. If you don't put it in deep, your mouth is closed to fill the gaps and the harp is out front where the sound is tinny. Hope this makes sense.
While tongue blocking yawn... this will help to drop the tongue in the back.