Désolé pour le smiley "

".
Je ne l'ai pas mis par rapport au topic (que je trouve intéressant).
Comme je ne suis pas capable d'y répondre moi-même (j'ai essayé...), j'ai trouvé ces définitions sur un site spécialisé dans le genre :
Psychedelic Folk Music :
"psychedelic" as a musical genre is often associated with "mindexpanding experiences", which are absolutely not necessarilly drugs-experiences. There are musical effects used, to express such an experience. In acoustic music, this could mean a somewhat open tuning and freedom for jamming improvisation, or even when there are casual semi-eastern / middle eastern influences to make an intuitive feeling of open tuning. I prefer to use the term 'folk-psych' when the starting point was psych and not acoustic music, while 'psych folk' has a starting point of folk.
Acid Folk :
At first I prefered to use this term especially for acoustic music which doesn't reproduce or start from traditional elements, but where it re-invents an acoustic folk like style structure, without being experimental in harmonies or melodies. Most of the time the style is a very personal expression for the specific group who reproduces it. Of course preferably, like in the usual sense, there must be some "acid" of the inspirations, a deeply inspired mind-freeing experience involved with it to really justify the use of the term.
http://psychedelicfolk.homestead.com/Ps ... cfolk.html