Mudcat Café message #4080449 The Mudcat Café TM
Thread #59200   Message #4080449
Posted By: Richard Mellish
21-Nov-20 - 07:11 AM
Thread Name: Relative Minor Key signatures?
Subject: RE: Relative Minor Key signatures?
This may or may not help. Feel free to ignore.

The order set out by leeneia applies if you stick to the white notes and start first on C, then on D, E, etc.

I think of the modes in a different order:
Ionian: white notes starting on C.
Mixolydian: flatten the seventh note of the scale, so start on C and flatten the B OR start on G and use F natural instead of F sharp.
Dorian: flatten the third and seventh notes of the scale, so start on C and flatten the E and the B OR start on D and use F natural and C natural.
Aeolian: flatten the third, sixth and seventh notes of the scale, so start on C and flatten the E, the A and the B OR start on A and use C natural, F natural and G natural.

Those four modes are all reasonably common in tunes from the British Isles, and there are some hexatonic tunes that leave out one note.

The other modes are very rare.
Phrygian with a flattened second, so D flat if starting on C, or F natural if starting on E.
Locrian (all the white notes starting on B) has a flattened second but also a flattened fifth, which means you've changed the next most important note of the scale after the tonic.
Lydian has a sharp fourth, F sharp if you start on C, or all the white notes starting on F, so you've lost another important note.

Then of course there are some modes from other parts of the world that don't stick to two tones, one semitone, three tones, one semitone. So for example you might have a tune with E flat and F sharp, giving a three-semitone interval.

I play one Swedish tune that is in G-minorish with the F always sharp, the B always flat and the C sometimes natural and sometimes sharp.

If you are not yet confused, you are not yet informed.