This is what we did in my lesson last night: 1) Teacher plays ii-V-I in key of F. 1 measure of ii, 1 measure of V etc. He had me improv some bepob lines over the progression - no fancy rhythm, just all eigth notes. Then has me put my guitar away and asks me to sing the same line. Its tough but I sqeek it out. Then he asks me to sing the same line in all 12 keys. Very difficult. 2) Then he plays some chords and has me sing the corresponding scale - i.e. he plays Cm7 and I have to sing C dorian. He plays Bb13b9 and I have to sing half-whole diminished. I can do the dorian but I crash and burn on the diminished 3) He plays a starting tone on his guitar. Then he points to the rest of the notes and asks me to sing them. I'm singing happy birthday while he's playing mary had a little lamb. This is why I am never truly improvising. I'm always playing canned lines and relying on intellect and memorization instead of relying on my ears. I think the effort I put into this will pay dividends if I'm diligent about it.