Quote (Eep @ Jun 21 2010 06:31am)
I do have 2 questions actually
2 points I never learned from my website...
I-IV-V-I, I-vi-IV-V-I, I-vi-ii-V7-I: these numbers you listed at the bottom...I've seen them before, what do they represent? Or do they just represent the tone/octave of certain keynotes/scales?
also, what is a diatonic chord? Don't think I've come across that either.
Ok, these "I-IV-V-I, I-vi-IV-V-I, I-vi-ii-V7-I" are chord progressions. Roman numerals in music theory represent chords built on certain scale degrees in a major or minor key. Arabic numbers refer to scale degrees themselves, the roman numerals represent chords.
So, if we take a major scale and stack it up in thirds (that's how most chords are built), we get the
diatonic chords of the scale. Diatonic means within the scale. Chromatic means outside the key, for future reference. So our diatonic chords are simply the chords we derive out of the notes within the scale.
If we're using C major: C D E F G A B C
We can build a unique chord off each degree of the scale, there are 7 unique degrees.
To stack a third we simply skip a note in the scale, add that note to the one we started with, then do it again.
C D
E F
GC E G, that is your C major chord. We call it I, because it is built off the first degree of the scale, and it's major. lowercase roman numerals indicate minor chords. º indicates a diminished chord.
So, if we do that throughout the whole scale we get these chords: C-Dm-Em-F-G-Am-Bdim, in roman numerals: I-ii-iii-IV-V-vi-viiº
We use the roman numerals to transcend the individual key itself and talk about the chord sequences as they relate to all major keys. For instance a I-IV-V could be played in any key, but it's always, relatively, the same chord progression - just in a different key.