I'm not going to get into this can of worms. I've been here before, and I'm always amazed at how people try to make hard work of something that really isn't that complicated.

MtheGM at 21 Dec 09 - 03:55 p.m. is right. If it's in a major key, the three major chords (tonic, subdominant, and dominant—major chords built on 1, 4, and 5 of the scale) are all that is really necessary.   You can use the relative minor chords as "color" chords if you wish, but for many folk songs, they should be used judiciously. Same with songs in a minor key. Accompany with the three primary minor chords, with the relative major keys usable as color chords.

In certain modes, the flatted 7th chord (Bb in the key of C, F in the key of G, etc.) may be called for.

But--get the regular major and minor keys down first before you start messing with modes. They, too, are relatively simple, but it's astounding how people seem to like to make hard work of something that's not really that complex.

Cripe! I wasn't going to get into this!

Don Firth