A little while ago, I explained the jazz tradition of quoting other songs during solos. One of the things I mentioned in that piece is that we do this to impress and amuse our fellow musicians, since we assume the audience doesn’t know enough about jazz to get the joke. Well, this comedian seems to agree:
And he has a point. A lot of jazz is pretty complicated. And to completely appreciate everything that is happening on stage or in a recording requires a lot of historical context. But there are some things in jazz that are actually pretty simple. And one of those things is the 2-5-1 chord progression.
Let’s start with the C major scale. CDEFGABC. If you number those C=1, D=2, and G=5. So for the key of C major, 2-5-1 is DGC. For any scale, the 2-5-1 means the second note, the fifth note, and then the first note (also called the “root”).
The first chord is 2, so we’ll start there. A D major scale has a F# and and C# in it. But we are going to bring those down a half step. So we are flatting the 3rd note (bringing F# down to F) and the 7th note (bringing C# down to C). In jazz, we call a flat third “minor” and we call a flat seventh “dominant seven.” We are going to play a Dm7 (D minor, dominant 7) chord. Why did we do all that flatting? Because we are lazy. Once you’ve done that to the D scale, it’s got the same notes as that C scale we started with. We’re just starting in a different place. DEFGABCD
The next chord is 5. A G major scale has an F# in it. Guess what we’re going to do to that pesky #. That’s right. Flat that sucker. So we are going to play a G7 (G dominant 7) chord. Again, this gets our scale back to the same notes as the C scale we started with. GABCDEFG
The final chord is 1. That’s plain old C, which we already covered.
So a C major 2-5-1 is: Dm7-G7-C. Let’s listen:
That is probably the most common chord progression in jazz. For example, the bridge in Angel Eyes is B♭m7-E♭7- A♭. B♭ is the second note of the A♭ scale and E♭ is the fifth note. (About the notation, in jazz -7 is another way to say minor dominant 7, and maj7 is another way to say plain old major scale.)
So why is it so popular? There are a few reasons, I think. First, it helps to understand that minor chords sound sad, and major chords sound happy. This progression starts at a really minor mood (flat 3 and 7), goes to a slightly minor mood (flat 7) and then resolves to a happy major mood. So it’s got a tension-release thing going on.
Another reason is that we are playing three different chords, but the actual notes of those scales are exactly the same. That makes it much easier on the soloists, because they can draw from a single scale for quite a while.
The last reason is that this progression is particularly easy on the piano player. To understand why, we need to cover something called voicings. I’ve been slipping back and forth between the words “scale” and “chord” as though they are the same thing, but they aren’t. A scale is all the notes of the key, whereas a chord is just some of the notes. There is no hard and fast rule which notes you should use. In church music, they always use the first, third and fifth note. Always. Boooooring.
In jazz piano or guitar, you choose which notes for your chord. And that set of notes is called a voicing. Let’s consider piano. What you are looking for in a voicing is to emphasize the notes that make that chord special. As you saw in our derivations, we tend to screw around with the third and seventh notes a lot, so let’s make sure we have those. We’ll stay away from the first note, since that’s the bass player’s job. 4 and 6 are just weird. So how about for the Dm7, we use F and C (3 and 7), and E and A (2 and 5).
For the G7, we use B and F (3 and 7), and A and D (2 and 5). See what I did there? Same voicing as we used for the previous chord.
And finally for C, we use E and B (3 and 7), and D and G (2 and 5). Same voicing again!
So we were really consistent with our voicings. Let’s look at the actual notes, in the order I played them in that video: CEFA, BDFA, BDEG. To get from the first chord to the second, I moved two fingers down one note and left two fingers where they were. To get from the second chord to the third, I—wait for it—moved two fingers down one note and left two fingers where they were. It’s like magic!
You can see how this is easy for the piano player. They are only moving a couple fingers each bar, and they don’t even need to move them very far.
So we have a progression with a tension-release feel, easy on the soloist, and easy on the piano player. That’s a great set of characteristics, so it became sort of the “go to” progression in jazz. It’s everywhere. And since it’s everywhere, it’s familiar, which is yet another reason to use it. Because people like songs that sound like songs they like.
So drink up, all you people. Order anything you see. And have fun, you happy people. The drinks, and the laughs on me. 2-5-1. So reliable, it even buys you drinks!