Originally Posted by: Mick JIf you play in the key of C major in a parallel mode (and it doesn’t matter which one) but lets say for example in the Dorian mode.[/quote]
The way you've set up the question here might be causing some of your confusion. To play in a "parallel mode" as you say is to imply a change of key signature. You seem to understand this because you go on to say:Originally Posted by: Mick J
The notation will show the key signature as having 2 flats (E and B), which is essentially, the key of B flat.
Precisely. :)
[QUOTE=Mick J]
So why is this called C Dorian and not B flat?
Good question.
Answer: it IS the key of B-flat major. C Dorian is the second mode of the B-flat major scale.
However, here is where is gets a little more complex: what if you play the notes of C Dorian, but never play the B-flat major chord, or refer to the B-flat major scale?
Essentially, this is modal theory as distinguished from tonal theory.
Until and unless you include the I & V chord playing or implying a V-I cadence (a tonal cadence) you are playing modally. The issue is that merely playing a collecion of notes does not give you enough info to determine conclusively what mode or key you are necessarily using.
Suppose you only play the notes C and D. What key are you in? What mode? You've ruled out C Phrygian and Locrian along with C-sharp major, but it could still be a lot of different ones you are implying. But you won't know without more info.
Play these chords: C minor, G minor, F major. Then, play a melody over those chords using C Dorian, you are playing modally, implying that C is your root.
Now change the chords: C minor, F major, B-flat major. This is a ii-V-I progression. Play a melody over those chords using C Dorian, you are playing tonally in B-flat major using C Dorian as a position of B-flat major.
Make sense?
I have more info on this here:
http://www.guitartricks.com/forum/showpost.php?p=222422&postcount=43
http://www.guitartricks.com/forum/showpost.php?p=222332&postcount=39
No need for apologies and you aren't asking stupid questions. These are advanced and often tricky concepts to get a handle on.
