A Question concerning the I, IV, V progression

The last couple of posts dealt with scales, chords, the Roman numeral system and how certain chords relate to certain scales. If you are using the C Major scale and you are deriving the chords that correspond to each tone of the scale, you would get, Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7b5. My question is how come the I, IV, V progression refers to all dominant 7th chords? For example, C7, F7, G7. The only one of those chords which would be directly derived from the C major scale is the V chord, or G7. Is it that the I, IV, V progression or in my example C7, F7, G7, is not actually derived from the C Major scale?

You're right, the only dominant 7th chord from the 1,4,5 progression derived from the C major scale is G7. The only reason I can think of is that 1,4,5 progressions are usually blues or rock, which is based on the pentatonic. Most of the notes from the basic triads are there, and the other notes just add flavor.

Actually, now that I think about it - if you look at the notes for those chords, you'll see that if you combine the C major and minor pentatonic scales all the notes of the 1,4,5 seventh chord progression are included therein.

Waaala!

all of music theory is based off the major scale system that was created by the Greeks thousands of years ago. The music and scales of the Blues, wich is mainly responsible for all of contemporary music,is only a couple of hundred yrs. old. People are always looking for some way of relating the 2 systems together (diatonic & Blues)but in reality they are very different from each other and should be approached so.
The harmonic and melodic approach to the blues is very different then the traditional diatonic system. The blues is based off of minor scales being applied over top of major or dominant 7th harmonies. The 1,4,5 progression is always referenced to the traditional diatonic harmony (1maj.7 4maj7 5dom7) unless otherwise specified (1dom7 4dom7 5dom7)
so to answer your question, the 1 4 5 prog. does not refer to all dom.7th chords unless the author is specifically refering to a Blues prog.

Originally posted by chris mood
all of music theory is based off the major scale system that was created by the Greeks thousands of years ago. The music and scales of the Blues, wich is mainly responsible for all of contemporary music,is only a couple of hundred yrs. old. People are always looking for some way of relating the 2 systems together (diatonic & Blues)but in reality they are very different from each other and should be approached so.
The harmonic and melodic approach to the blues is very different then the traditional diatonic system. The blues is based off of minor scales being applied over top of major or dominant 7th harmonies. The 1,4,5 progression is always referenced to the traditional diatonic harmony (1maj.7 4maj7 5dom7) unless otherwise specified (1dom7 4dom7 5dom7)
so to answer your question, the 1 4 5 prog. does not refer to all dom.7th chords unless the author is specifically refering to a Blues prog.

I understand your point regarding the application of the I, IV, V as it applies to diatonic harmony as opposed to blues. And maybe I should have been a little clearer in my use of terminology. I'm just wondering if all of the notes which make up the chords of the I7, IV7, V7 progression are contained in one scale, similar to the way that all of the notes which make up the chords of the I, IV, V are contained in the Major Scale.

Like said, if you look at the notes, you'll see that it's a fusion of major and minor scales. For the I7, IV7, V7 progression starting from C, you have to combine the C major and C minor scales to get all the notes.

I had to write this one out to see if you were correct, and although you were pretty close there is one flaw in your theory....the major 3rd of the 5 chord is not addressed in either scale...so in fact the combination of Cmaj blues and C minor blues would outline a G minor 7th chord.
I think the answer to trebledamages question is no...theres is no one scale that outlines the dominant 1 4 5 progression.

True, there would be no B note if you combine the major and minor pentatonic scales only. But allow me to make a revision. In my last post, I didn't say pentatonic. I said major and minor scales, all seven notes of each scale. If you combine the C major and C minor (Eb major) scales, you get all the notes in the 1,4,5 seventh chords.

:cool:

O'kay, I decided to follow Chris Mood's example and not try and fit the I7, IV7, V7 progression into traditional diatonic theory. (Because they simply don't seem to fit!) Some projects are best left unfinished.

I Know a scale that contains all the notes of the dominant 1 4 5.....The Chromatic Scale....-LOL-

LOL. It is settled then! The chromatic scale is the basis for I7, IV7, V7, I, IV, V, and all life as we know it!

Well, it's not entirely chromatic. There's no C#, no F#, etc . . .