Sorry- pressed the wrong button and the message got sent before I was done.

Phyrgian is pronounced: frij-ee-un, btw.

from F to F all white keys: lydian mode. Major sounding except the 4th pitch is a 1/2 higher than true major/Ionian. So you'd have a b natural instead of a b flat. A bit odd sounding for most of our ears.

from G to G: mixolydian mode. Sounds like major except for the flatted 7th, an f natural instead of an f sharp. Ol' Joe Clark leaps to mind. Very popular in old-time music.

from A to A: aeolian mode. What we call nowadays, minor. Actually, natural minor because there are some alternate minor keys.

from B to B: locrian mode. Rarely used cuz it just plain sounds wierd.

The modes were used in ecclesiastical music in the Middle Ages. They are also called the church modes.

To put too fine a point on it: major and minor are types of modes called ionian and aeolian, respectively. Since the middle ages, we've gradually lost the preference for the wonderful variation created by the modal tonalities and have ended up settling almost exclusively on major and minor. I think one of the reasons we love some of those old ballads so it that they are NOT major/minor but rather modal.

BTW: you can do the little progression you were talking about it in more than one mode. It works very well in aeolian (like an a minor to G major shift) too.

If you were a harper with a natural harp (no way to change the strings up and down a half-step like some can nowadays) you would almost certainly end up playing modally. It would be just like using only white keys on a piano. That explains to my satisfaction why so much Irish-type music has an interesting harmonic flavor.

This is probably more information than anybody wanted to know.....
Martha in Tallahassee