In reply to C E MORGAN,The mist covered mountain was written by junior crehan, and he performed it in g mixolydian with an f natural.I personally think that this is what gives the tune its beauty, of course you are free to play it how you like,but that was not the way Junior Crehan intended it.all the modes are just another name for scales with altered intervals, including the major scale.you can of course play modal chords in standard tuning, its just they are more difficult than say d ad gad or dadeae. from my own experience you dont get the ringing strings effect in standard tuning.finally the dominant seventh can be used for modal tunes if you omit the third note of the chord. g modal dominant 7 is g d f nat.