I've been playing about 3 years plus, going thru the standard method books with a good teacher, but can't seem to get started improvising. The funny thing is that I can play by ear pretty well, if I can hum it I can play it - sometimes right off with only a couple wrong notes. And sometimes I can get behind a slow blues number and fool around with the blues scale. What I would really like to do is to play behind, or with, other instruments andor accompany a soloist, rather than blowing a complete improvised solo. Anyway, it would seem if one can sing along a bit, and play by ear, you could also improvise but that's just not happening. Any ideas of what's wrong?