Originally Posted by: ShootaMcgavinbut there's a slight problem: A major's Dorian is in B.

This is a source of a lot of confusion.

A Dorian is not in B at all. A Dorian is A major with some changes.

It happens to be the case that A Dorian scale has the same notes as G Major scale (not B, you went in the wrong direction).

It can be useful to know this. If you know what the "Dorian" sound is like, and you want to achieve that sound against A chords, then you can actually play the notes from "G major" scale and guess what, you will be playing A Dorian.

A Dorian: A B C D E F# G A

G Major: G A B C D E F# G

However, it's not so simple - you still need to know what you are doing. If you play G major scale, focusing attention around the notes that make the key G major - the 1,3 and 5, which are G, B and D, then it won't sound much like an awesome A Dorian solo, it will sound like a fool playing G Major over A chords.

To get the A Dorian sound you would need to focus on the 1, b3, 5 and 6 (since 6 is what is special about Dorian). These are A, C,E and F#.

Notice how all those notes are from G major, but not the ones you'd normally emphasise in G.

BTW, if you are interested in a quick way to experiment with what does each mode sound like, I recommend this you tube video.

Make sure you close your ears when he says "modes will make you into a star". However, his description of how to quickly "experience" each mode is maybe the best I've seen.

HTH

GaJ