Thread: Chord Structure
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Old April 30th, 2007
Fretsource Fretsource is offline

Playing guitar for what seems like forever.
 
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Quote:
Originally Posted by hb View Post
I have always thought of songs as "keys" and not "modes" , but I guess in a round-a-bout way they're kinda equivalant.

hb
That's right - They're more or less equivalent.
Strictly speaking, the mode of a song refers to the arrangement of the tones and semitones, (such as TTSTTTS = major or Ionian) and the key refers to the pitch of the main note (key note).

So when we say a song is in the key of C major, it really means, the KEY note is C and the MODE is major (or, Ionian)

That's why it's called a KEY - when we apply that strict order of tones and semitones of the mode to any starting note, it UNLOCKS the whole SCALE of notes, giving us the key note and mode.

So if you take the major mode (Ionian mode) which is always TTSTTTS and apply it to any note, say F, it UNLOCKS the series of notes F G A Bb C D E F - and that is the F MAJOR scale (or F Ionian mode) and if we compose music using those notes around the main note F, we get music in the KEY of F MAJOR

Nowadays we just call the modes either major or minor when talking about keys. We don't usually say a song is in the key of F Ionian, we just say it's in the key of F major.

Ionian, Lydian and Mixolydian are major modes
Dorian, Phrygian and Aeolian are minor modes
Locrian is an exception and was never part of the key system.

Modes still get called by their old names (Ionian, Dorian etc.) when used as melodies for improvising, as in Steve's very informative lesson on modes.


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