V - I vs. I - IV

[groovyjazzyfunky]

I was listening to a song tonight which used the chord progression E - A throughout the entire song. I have a good ear (top of my ear training class in college), and it was obvious that the progression was V - I, with the song being in the key of A. The question that's driving me nuts: *Why* was this obvious? Arguably the majority of songs utilizing an E - A progression are in the key of E, with those chords being a I - IV progression. So what makes an E - A progression a I - IV in one song, but a V - I in another? Is it the melody? Could I lay down an E - A bass groove and have it magically "change key" depending on the melody being played on top of it? Perhaps I'll do some experimenting.

 

Man, it's been way too long since I buried my nose in a good theory book.

[the.circular.motion.rub.it]

sorry nothing to say...

 

but dude, i hear ya...

 

this kind of stuff fascinates me...

 

maybe treating it as a V - I instead of a I - IV (or whatever) would give the song/melody/harmony/what have you, a different flavor, similiar to, say, using a different but relative mode to what it would normally be...

 

err, if you know what i mean...

 

i think im going to need to be doing some experimenting too

 

errp... peace

[davebrownbass]

Actually, the answer is much simpler than you might imagine.

 

If E-A is a V-I, it's because E is the V chord in the Key of A (and A is the root chord of that key.)

 

Because of that, the melody will be in A, with 3 sharps ONLY....F#, G#, C#.

 

If E-A is a I-IV, it's because E is the root chord in the key of E (and A is the IV chord.)

 

Because of that, the melody will be in E, with 4 sharps....F,G,C AND D#.

 

In fact, you can play games with this. Have somebody loop these chords (or do it on your computer) and then run scale fragments with F, C and G #. Play the scale with D natural and you'll hear the A functioning as a I. Then, in the middle of this experiment throw in the D#. Like magic, your universe will shift, and you'll hear the chords with E functioning as I.

 

This small chromatic moment has been brought to you by all the composers of Western harmony for the past 600 years. Bach understood it; so did Charlie Parker. It's amazin', ain't it?

[soupster]

you answered yourself man, you change keys. when you do that the I changes, and the octaves move for the progression. I think you know this, i think you know that neither E or A or changed in eithers key sig, nor the chord qualities. You can tell whats I because of the key. maybe im an idiot and just cant read what your saying.

[musicalhair]

To put another spin on Dave's fine explaination, what your hearing is the release of tension when the change gets to A. Your hearing the cadence, probably one of those really nice perfect cadences that really drive home the feel of a V-I change, instead of the like shift of weight that feels like a I to IV change and then the Plagal cadence that comes back from IV - I.

 

But all these "feels" and sounds are a result of the Leading tone G# resolving up to A and voice leading stuff like that.

[groovyjazzyfunky]

Thanks for the explanation, Dave. But... say I'm doing some sax soloing over an E - A bass groove that's "intended" to be a I - IV in the key of E. And say I'm staying away from the D#, but instead am flatting it (the 7th). Which I actually do quite often in my sax soloing. So why doesn't it make that I - IV in the key of E sound instead like a V - I in the Key of A? Or the other way around -- I'm playing over a V - I in the key of A, but throwing in lots of D#'s (augmented 4th) for that good tritone nastiness. Why doesn't that make it sound as if I'm playing over a I - IV in E?

 

I'm thinking I likely know all the theory I need to know in order to answer my own question, but probably what it comes down to is: What key does it *sound* like I'm playing in? Perhaps if I made a conscious effort to "play in the key of E" whilst playing over a V - I in A, it'd either sound like I was in E, or it'd sound like I was really out there. Probably all depending on how grounded in either E or A the rest of the band is.

 

You know what I'm thinking would be really fun? I'm going to try writing a pop or rock song with just the chords E - A over and over, ad nauseum. The verse will be a I - IV in E, and the chorus will be a V - I in A. I wonder what it'll take to make it so that I'm obviously changing keys, but keeping the chords exactly the same. Hmmm.

[davebrownbass]

That would be an interesting project.

 

I think musicalhair gives us a clue to the dilemma.

 

The specific resolution that makes E7-A work is the tritone in E7: G#-D...resolving to A-C#. Of course, this is also present when you change to the key of E with the progression I I7 IV (using E as a secondary dominant. When the A chord is IV, does it want to resolve back to the I? How about when it's an A7 (as in the blues changes)?

 

For some reason, the song "Evil Ways" from Santana keeps ringing in my head right now.

[Jode]

Lots of modern-day popular music is modal, and doesn't fit neatly into the Western tonal model. A two-chord vamp, say, Em7 to A, since someone mentioned "Evil Ways," would actually be a ii-V progression in 'legit' harmony. But it's a rock song with a definite tonal center of E, so it's a i-IV progression in E Dorian.

[groovyjazzyfunky]

Originally posted by Jode:

Lots of modern-day popular music is modal, and doesn't fit neatly into the Western tonal model. A two-chord vamp, say, Em7 to A, since someone mentioned "Evil Ways," would actually be a ii-V progression in 'legit' harmony. But it's a rock song with a definite tonal center of E, so it's a i-IV progression in E Dorian.

Many, many minor-key songs use major IV and V chords, which I simply attribute to the raised 6th and 7th tones of the melodic minor scale.

 

A song with only a ii-V progression? That might be interesting if you could make it work. It'd be a turnaround that never resolved. Is that even possible? Could you write a whole song in the key of C that never actually hits a C chord? Would it sound like it was in C?