Chord Progressions from 25,000 Songs

[BLUMENKOHL 1,068]

Source:

http://amitkohli.com/?p=246

Explaining the figure a little bit: What interests us here is the type of chords used, regardless of the songs scale, so that 1->5->6 in the figure above includes songs in key of C major that have the chord progression C->G->Am and songs in the key of A major that have A->E->F#m (if the songs have the same Roman numerals and are in the same relative major. In reality, the API blends songs into rough categories regardless of the songs mode, so its impossible to know for sure what were dealing with).

The chord progressions start from the left, and continue to the right. So for example, the transition 4->1->5->6 is one of the most popular ones and is in fact present in 327 songs!

Protip: If you're on 5, go to 6!

[Sharkissimo 1,973]

Why are the doors opening?

Fascinating to look at, though there's not much you can gleam from it, except that most four chord songs start on the tonic (I), subdominant (IV), dominant (V) or submediant (vi). It works as a piece of digital art, though.

[Ludwig 1,120]

Below is something similar I've found very informative. It's from an academic study of 100 songs from Rolling Stone magazine's "Greatest 500 Songs of All Time" list. Basically, these authors took the 20 highest-ranked songs of each decade from the 1950s through the 1990s, then analyzed the harmony in all. The table shows the number of times chord X (on the left-hand side) goes to chord Y (along the top) in all the songs.

What is most obvious is that the most important chord besides the tonic is not the dominant, but the subdominant. In other words, the most common chord successions are IV-I and I-IV. There's a ton more that can be said from these numbers too. I thought it was very interesting.

EDIT: I should add that the chords listed include all chord qualities of the same root, and inversions as well as chordal extensions (7ths, 9ths, etc.) are excluded. These are simply the roots of the chords.

[Glóin the Dark 1,224]

Here's an eight-chord progression in which each successor is the least (or joint least) popular according to that table.

I - #IV - II - bVI - III - bII - V - VII

Now to come up with the most unpopular melody ever to accompany it...

[Dixon Hill 4,234]

That actually sounds great.