hi dave.......i have only the most vague idea about these and am interested in how they work.....is there good source material available......i have a decent grasp of the modes and arpeggios but making music from it all seems far away still......thanx jc

Hi Jim, When you are aware of the key center this allows you to improvise over the music thinking of a a tonality other than each particular chord. Bass players, at least when playing bass lines are thinking the chord of the moment. But when you know a key center and you know diatonic harmony you can recognize chord progressions much more easily than otherwise. I am sure there are plenty of resources out there but I do know that the knowledge I have about the subject are in my Complete Electric Bass Method Books Beginning, Intermediate and Mastering. My Total Jazz Bassist book goes into this subject in great detail also. They are all published by Alfred. If you type my name into a search engine you'll see these books on many sites.

Let me know how it goes.

Dave