i'm new to this forum, be gentle. i come from a jazz background in music , guitar mainly but also a little trumpet.

with folk music, it seems as all the tunes r harmonically simple, you can really play whatever you like.. isn't that the point? you arrange it to suit your style? for example... over a G major based melody.. e.g notes-

G A B C D E F#

You can play secondary harmony (e.g m7, MAJ7, DOM7, b7#5) if approached in the right way..

That seems symptomatic of an attitude you often get from jazz musicians coming into the folk scene - i.e. condescension and contempt for the material.

No you CAN'T play whatever you like. Folktunes have their own expressive world, we do NOT see them as simply something to egotrip over. They are tiny, but each one has been be shaped to say something unique.

I think this attitude in jazz comes from the period in the mid-20th century when it derived much of its raw material from Broadway ahows. That material was garbage - sentimental slop, aural security blankets for white Readers Digest readers - but the mostly black jazz musicians of the time had to use it because that was where the money was. So they spent decades steadily tearing the stuff up and reworking it beyond the point of recognizability. They knew their raw material was shite and treated it accordingly. The result was often brilliant, but it was an artistic triumph that succeeded in spite of its origins.

We do NOT appreciate our tradition being treated as if it was Cole Porter or Lerner & Loewe, thanks.

Actually the nastiest example of jazzifying folk I can think of doesn't involve harmony at all. It's Annie Grace's take on "The Trees They Grow So High". She distorts the rhythm and dynamics to make it sound like a Billie Holiday number. It's completely inappropriate to the content of the song, just pisses all over it.

look at Bellowhead, or that collaboration that never made it- Paraellagram

I only know the Bellowhead "E.P. Onymous" CD and wasn't very impressed (mainly because of the lead vocalist's terrible breath control, gasping for air at the end of every phrase).