If i were to sit down with a couple o' guys, to you know, just jam in "Bb," would i use the Minor pentonic and its progression, or the major with its progression? Because i've noticed that, say, A7 works well in the Aminor pentatonic box, but its not in key! What do i use? major or minor? Or shouldn't i care? I heard that blues has less rules than classical music.

All i want to know is when someoen in a blues band says Bb or A, do they mean Major, or Minor?!