Theory behind I iii IV V

Question

I am doing my best to book-learn and keyboard-hack my way through jazz piano. I've recently started trying to swing this progression/combo, but do not quite understand the theory of why it works.

[ I iii IV V ] with a roll from the "minor third" to the "major third" of each chord (is that the right generalization?) i.e. C-Eb/E-G, E-Gb/G-B, F-Ab/A-C, G-Bb/B-D

It seems I run into these progression -> theory translational errors quite a lot and I am unsure how to climb to the next learning curve of the theory to where I can do the translation on my own. (or at least clearly understand what I'm playing in generalizations)

Questions: How would I describe this progression? With respect to music theory, is there a particular reason it "works?"

Thanks for any insight into how I may intellectualize this particular playing. In the mean time more reading and more practice Thanks, John

Answer 1

Examining I iii IV V

Let's translate the progression into the key of C major just for simplicity. In C major, I is the chord C major, iii is E minor, IV is F major and V is G major. You didn't really specify the timing of the chords, so I'll assume, like other answers did, that you're referring to each chord taking up an entire bar as shown below:

This progression can be viewed as a I, I, IV, V progression, which is a common progression (will be explained why it works more below). Some argue that chords in a lot of music can be broken down into either the I, IV or V chord. So where does the E minor chord fit in? It's called a chord substitute. All chords have substitutes that they can use. C major has the notes C, E and G. E minor shares most of those notes since it has E, G and B. The iii chord is a good substitute for the I chord. We can say that I and iii share the same function in this chord progression. There is another good substitution for the I chord, it's vi (ACE). For the IV chord, we can substitute with ii or vi and the V chord can be substituted with iii or vii° (but you may find vii° to be a strange one). Here are a alternate chord progressions based on this concept:

Original: I, iii, IV, V Alternate 1: I, I, IV, V (substituted iii with I) Alternate 2: I, iii, ii, V (substituted IV with ii) Alternate 3: I, iii, vi, V (substituted IV with vi) Alternate 4: I, iii, IV, iii (substituted V with iii) Alternate 5: I, I, ii, V (in jazz, ii is more commonly used when going to V) Alternate 6: I, vi, ii, V (very common jazz progression...see if you can figure out the subs) etc

This is part of the answer.

Why Does I iii IV V Work?

When we design a simple progression in certain genres of music (classical, pop, rock, etc), we have two things:

1. Movement away from "home":
   a) "Home" is another way of referring to the tonic. The tonic is the chord that produces the least amount of tension in a chord progression. In this case of the key of C major, the chord C major is the tonic, but if you're in a minor key like A minor, the A minor chord would be the tonic. If you're in a mode like F Lydian, F major would be the tonic.
   
   b) In most progressions, the tonic is followed by a series of chords that add interest to the progression, but also create tension.
2. Movement back to "home": This is known as a cadence. The most common cadences in traditional music theory are the V to I cadence, which may be a point of resolution for your I iii IV V progression after the V chord. Another common cadence is the IV to I cadence. If we're in a minor key, V to i is very common. Modes do not usually for the V to I trend, but they have multiple cadences for each mode as well, depending on the mode.

In conclusion, when creating a chord progression, decide on a key, start with the tonic of that key, add chords that move away from the tonic and then make your way back to the tonic by the end of the phrase and you'll be making great chord progressions in no time.

Answer 2

The easiest way of conceptualizing this progression, especially with the goal of transposing it, is to view it as a simple I--IV--I progression with a passing tone.

In the above example, note how the basic I--IV--I of C--F--C is embellished with a simple passing tone in the upper most voice. Just go play this in a few keys to get a sense of how easy it is.

Now, two things happen. First, we harmonize that B passing tone with an E in the bass; now this passing tone becomes a bona fide iii chord. Secondly, I embellished the melodic line a little bit, but we still see the obvious skeleton of the scale descending from tonic to dominant. This is "Puff the Magic Dragon," and if you can play this, you've got the I--iii--IV--I progression down.

Edit: Well, crap. The moment I hit submit I see that you're asking about I--iii--IV--and then V. Screw it, I'm leaving it up. Just throw a V in right after the IV! :-)

Answer 3

The reason the progression works is because it follows the typical pattern of tonic I, tonic iii , sub-dominant IV, dominant V resolving (presumably) back to I. The general idea of a progression is to create tension and then resolve it.

The sub-dominant chords want to move to dominant chords (in the listener's ear) and the dominant chords to tonic.

Chord progressions are one way of creating tension and resolution (there are others of course) and creating tension and resolving it is generally considered the essence of composition/improvisation in music.

Answer 4

First off, the 'rolls' are harmonically irrelevant.

I'm not sure what your question is. But you don't need any excuse to use a sequence of chords all formed from the notes of the same scale (C major in this case), particularly when there's a strong melodic bass line and consecutive chords have one or more notes in common (were you particularly worried about the E minor chord?)

Always remember, musical theory is not a set of restrictions, telling you what you are ALLOWED (or not) to do. It's an open-ended set of descriptions of things that have been found to work. Yes, I iii IV V is a common pattern. Put it in your box of musical tricks. Carry on!

Answer 5

Some thought here. It seems you want to understand "why a progression works". In short, no one knows. This is a very deep question. In what sense? Biology, psychology, or tradition, or...? I have discussed with psychology and music students who are my friends, but to this day none has given me a satisfying answer.

However, there are some rules regarding "what progressions usually sound good".

• moving up a fourth, moving down a third, moving up a second, are all natural.

• moving down a fourth, moving up a third, moving down a second, are all strange.

In your case of I -- iii -- IV -- V, a strange progression (up a third) is compensated by two natural progressions (up a second twice). In fact, the reassurance from V to I is so strong that it gives a sense of ending, which is why . You can play around with the two principles I listed, and you will "rediscover" many familiar progressions widely suggested in books.