I love this thread. Generally I try to avoid the theory forum these days because of threads such as this.
Music is art. It's not literature nor is it science. Simply because one person hundreds of years ago had a theorum on modes or it had a specific purpose at a point of time does not makd that statement always true. The word travel came from another similar word that did not mean transportation
travel (v.) late 14c., "to journey," from travailen (1300) "to make a journey," originally "to toil, labor" (see travail).
Modes and modal playing has evolved from centuries past to a new context of which altruist/historians cannot accept. We are a dynamic (changing) culture we artisans / craftsmen who use music as our canvas. In the education of music one can simply utilize knowledge from cenuries old text that may or may not be relevent to real world situations of contemporary music. If one is to teach from purely a middle ages mentality then one should at least acknoledge that cultural developments have changed the landscape and context of music. Modes applied to jazz were applied not hard and fast to the standards set forth during earlier centuries. Jazz musicians are artisans crafting ideas to their will, not the other way around. The experiments with coloring outside the box and not being bound to older standards lead to the creation of new approaches which became standards. Jazz is dynamic in it's nature. The constructs of early jazz are not always present or evident in later forms. Jazz musicians made their own stands and follow their own schools, Usually they are perfectly comfortable using different "schools" of comtemporary music over a career. Just as Piccasso originally started as an impressionist then moved away to the style of painting we recognize him most for that being Cubanism.
There is a huge difference in the fields of jazz/blues vs the fields of pop/rock. In pop/rock/country the main goal is to "play it like it is" and that can be very rewarding in and of itself. In Jazz/Blues while a set form exists for the original melody and harmony there is greater freedom of interpertaion not just limited to the soloist. There is a communication going on between the musicians on a different level and there also is an opporituntity for exploration within the framework. Much much more so then could be attained in classical settings.
Classical musicians at one time had greater control of thier own performances however this is mostly reigned in by the overly detailed sheet music and what little is left is dominated by the conductor. He's doing much more then keeping time with that stick he is directing minute aspects in performance.
Regaring B.B. King
BBK was a pragmatic student, What doesn't apply to the field he's doing he casts off to the side. This is something every musician should learn to do. Discriminate what works for them and what doesn't. Music is not simply one form of art. It's several. You may not be able to endeavor in all art forms best to the method that works for you and acknoledge that other forms which may be equally valid may not work for you.
He is a sharp listener and continues to be at the forefront of the Blues, He is the elder statesman of the style. He's been a freelance columnist for Guitar Player and several other magazines long before I was born (I'm in my 50's) and he still offers sage advise to up and coming blues musicians as well as seasoned ones. If you don't believe me ask Joe Bossona. BB King still has a packed tour date. He's the hardest working blues man out there and doesn't have to teach. He fully acknoledges that others can teach the blues just as well.
That's BB King.
Regarding personal tastes. Personal tastes in music are exactly that. Personal. There are forms of music that do not speak to me. There are forms of music that do not speak to you. If deride them or reject them then in a very real sense you are rejecting and deriding the music you claim to love in one way or another. A more pragmatic approach is simply to state "It's not my thing" I don't have to love the music you love and you don't have to love the music I love. Hate on the other hand is insulary. When one starts building walls on hate the walls rise and surround you. Till there is nothing left but you in a coffin of your own making. Doesn't it make more sense to simply enjoy what you like and focus on your enjoyment rather then live a life filled with rage and hatred?