Modes & Keys

my quick way of explaining it (off the top of my head) is that a mode tells which note of the key that the tonality of the song is based around.  So your key tells you what notes are flat and sharp, the mode tells you which step of that key is the root, or main tonality of the piece.  The mode isn't displayed on sheet music, but can be found out pretty simply.

Utah Man wrote: on sheet music, the musician is given [next to the treble clef] the time signature 3/4, 4/4, etc. and the key the piece is in...so where's the mode indicator ?

Actually the "key signature" (between the clef and the first notes) indicates both key and mode. For example if  it is empty it indicates C ionian (pure major) or any of the 6 other modes which use the same notes (for example A aeolian (pure minor), D dorian, E phrygian etc.).


Edited by MikeEnRegalia - November 22 2007 at 06:22

Sheet music doesn't give any information about mode...nor does it need to.  The key signature tells you what scale the entire piece or section of the piece is written in.  The modes of a piece alter every time the chord changes.  For instance a piece in C major - the key signature is C major.  If the first chord of the piece is C then the first mode used will be C Ionian.  If the second chord used is Am then the second mode used will be A Aeolian.....BUT the key signature is still C.  Key signature and mode are not directly related.  Modes are a way of thinking about chords as scale shapes instead of chord shapes.  You could write a piece of music that is based around the mode of B Locrian, a nice weird jazzy dreamy crazy sounding song....but the key signature would still be C as B Locrian as a mode only appears within the context of the key of C.

MikeEnRegalia wrote: ^ of course with any given (modal) key signature the piece (or part of it) could be in 7 different modes. In conjunction with the chords and bass notes played the mode can be deduced. But I wouldn't say that the mode changes everytime a chord changes ... for example if the key signature is C major and the piece starts with a Dm7 chord this signals D dorian, and if then the chord changes to G7 and back to Dm7 again the whole piece is a textbook example of D dorian. If on the other hand in a different section the chords alternate between G7 and F major it might suggest mixolydian ... The most important things about modes is that they're often ambiguous. One scale can be interpreted as 7 different modes.

/\ -- Yes, you can have one song in C major with many different modes, if you wanted. As far a songs go, I can't really help you.. but what you can do is this:

1. Go to your piano
2. Play the tones C, D, E, F, G, A, B, C. Congratulations, you have just played a C major scale. This is in a key with no sharps or flats (conventionally called C major).
3. Now, play the tones D, E, F, G, A, B, C, D. Congratulations, you have just played a D Dorian scale -- hear the difference? Notice that even when starting on D, you do not use the two sharps usually associated with the D major scale. You play all naturals. Starting one step above the first note of any major scale will give you the Dorian mode. You have just played this.
4. Still confused? Don't be. I have written some counterpoints to help you understand the differences in modes. All are in the same key: no sharps or flats. Each, however, is started on a different note.

Phrygian -- Starts on E.
http://koopaslaya.googlepages.com/PhrygianClarinet.mid

Dorian -- Starts on D
http://koopaslaya.googlepages.com/DorianClarinet.mid

Ionian -- Starts on C (Typically referred to as a major scale)
http://koopaslaya.googlepages.com/IonianClarinet.mid

Notice: Each example uses only one key signature. This is no sharps and no flats. The reason they all sound distinct is because of the mode I used. This is the root of the entire counterpoint. Oh, and I forgot to export them all in strings and clarinet, which I should have done. But, you'll get the picture... I hope.

5. Still confused? Get this book: The Study of Counterpoint, by Johann Joseph Fux.

Maybe this will help you:

Part 1: http://uk.youtube.com/watch?v=LWHKeC4IEgA&feature=RecentlyWatched&page=1&t=t&f=b

Part 2: http://uk.youtube.com/watch?v=BoGQ9yHOyZQ&feature=related

These helped me alot :)

Utah Man wrote: this input helps... i'm still a little . but do you guys know of songs - any songs - that would clearly demonstrate the difference between keys & modes ? If I could actually HEAR a song in such and such a mode it would help. OK...so in theory you could be in C major & utilize several different modes within that one key ? .

Edited by HughesJB4 - May 01 2008 at 04:41