On 2002-03-12 15:40, WhistlingGypsy wrote:
Are these the same things - i.e. D and B minor and G and E minor. Can someone explain.

Doh!
They are sort of the same thing. Well, they are related.
Here, take your D major scale: It goes
D - E - F# - G - A - B - C# - D.
If you look at the intervals between the notes, you get this (“1” means one whole tone up, “0.5” a half-tone):
1 - 1 - 0.5 - 1 - 1 - 1 - 0.5
As you see, two intervals on the scale are half-tones. That is the same for every major scale and in order to get a major scale starting on a different note, you have to use sharps and flats to get the half-tone intervals in the right place. D major has two sharps, F-major has 1 flat, and F# major has six sharps (ugh…).
You produce a minor scale by putting the half-tone intervals in different spots in the scale (this has nothing to do with what note you start on, do you follow?
). For instance, here is E-minor, written out as a scale:
E - F# - G - A - B - C - D - E
These are the intervals for a minor scale:
1 - 0.5 - 1 - 1 - 1 - 0.5 - 1
As you can see, the half-tone intervals are in a different place. That means that major and minor scales starting on the same note are going to have different sharps or flats. G major has 1 sharp, but G minor has 2 flats.
Each major scale has a related minor scale. They are related because they have the same number or sharps or flats. Of course they are going to start on different notes because the half-tone intervals have to be in different places. And, surprise, surprise, B-minor is related to D-major (both have two sharps), just as E-minor is related to G-major (both have one sharp.
Look at this little illustration:
E - F# - G - A - B - C - D - E - F# - G
|---------e-minor------------|
|----------g-major-----------|
Once you understand that you can create different kinds of scales by leaving the number of sharps and flats alone but starting on a different note, you have also understood those mysterious “modes”. Major and minor scales are just two out of seven possible modes (test question: why are there seven modes?).
For instance, if you want the Dorian mode, you start one note above the note that you would start on for a major scale (also called the Ionian mode). If you use two sharps (F# and C#) you get D-major (Ionian) and E Dorian and B minor (Aeolian), and incidentally A Myxolydian which you will also see in IrTrd. (The other modes don’t crop up much.) Test question: Where are the half-tone intervals in a Dorian scale?
Caveat: There are actually different kinds of minor, with different half-tone intervals going up and down, but nothing to worry about for IrTrad purposes, really.
Hope this helps. It certainly got longer than I though it would. :roll: