Help! 16 years Ive played most of which was spent in a rock band focussed on being rock stars over musicians. I have taken 3 years of Jazz lessons and learned many standards,my modes,i know my neck and have great fingering as well as right hand. I can learn most any thing put in front of me. I.e just finished Jaco's "Come On Come Over" including the chorus. But I just cant seem to get any better at freestyle jamming. Or just playing a great Bass line when I sit down with a unrehearsed group. How can I get better at creating a line??