The word “sub”(dominant) means below. In the key of C major, the fifth degree above the tonic is G, or G dominant. A fifth below C is F, or F sub-dominant. Chris is right, each one of these chords is completely different especially functionally. Take the circle of fifths, where I think the functionality is more acceptable. A dominant chords makes the progression sound ascending in the circle of fifths, and the subdominant sound descending. With or without theory terms, just aurally. If you were to modulate, the G dominant helps move up in circle of fifths, while F subdominants helps moves down in the circle of fifths. With a little help of other chords that would have to exist within either progression, although the F subdominant is a direct modulation to the key of F major. Not to be taking strictly, because there are many ways to work around it and manipulate. But this is a basic understanding of the dominant and subdominant function and meaning.

I-IV are iffy, try vi - IV. I-IV is a suspension because it wants to move back to I or even up to V. vi-IV is the foremost progression to get to a key a fifth below where you are now. Like the F subdominant directly to F major.

The Tritone is so hated because 1 its so hard to sing and 2 it is discord compared to all the other intervals. Funny thing is through all that time it was still used, but disguised. The common porogression F, A, B, C (typical Gregorian chant) or chord progression below.


e:----------3---
b:--5---7---5---
g:--4---7---5---
d:--6---7-------
a:--7---5---3---
e:--------------


This is an extremely common progression (in that period)that is clearly tritonic but is disguised. In moving from the first to the second sonority, the M3-5 progression of the lowest voices involves the tritonic relation of g#-d; in moving from the second to the third sonority, the M10-12 progression of the outer voices involves a similar relation of f#'-c. .

[Edited by noticingthemistake on 07-05-2003 at 11:43 AM]