
Chord progressions of 25,000 songs - joubert
http://amitkohli.com/?p=246
======
pcsanwald
If anyone has interest in harmonic theory and why I/IV/V progressions are so
pervasive, I highly recommend "The Harmonic Experience" by W.A. Mathieu.

He really gets into the harmonic series, and how intervals are really low
prime ratios.

I read this book after being a professional musician for 15 years and it was
an ear opening experience. there are lots of great singing exercises for
really hearing the overtone series.

it's pretty much the "art of computer programming" for music.

~~~
mhax
That book looks really interesting - thanks for the recommendation.

What still twists my melon about harmony is the Pythagorean Comma.

Harmony equating to integer ratios seems so right... But the fact that a
perfect 5th on a piano isn't _really_ a perfect 5th troubles me at some
existential level.

~~~
analog31
In my view all it means is that an approximation of perfection is good enough.
And the notion of temperament only really applies to keyboard instruments.
Strings are tuned to perfect intervals, and even 'good' intonation of fingered
notes is a matter of interpretation. Wind instruments are a hodgepodge of
compromises.

~~~
yellowapple
> Wind instruments are a hodgepodge of compromises.

It depends on the wind instrument and the setting.

For woodwinds, yes, this is typically true; it's very difficult to adjust the
tuning of a particular note on-the-fly.

For brass, however, this becomes less and less true; more sophisticated brass
instruments will have easily-accessible "tuning slides" (in addition to the
main one) meant to adjust the tuning of a particular note, making them well-
suited for situations where absolute tuning is necessary (it's really useful
for brass-only ensembles) _and_ where temperament is dominant (like orchestral
and symphonic settings).

This is taken to the extreme with the trombone, which is basically just a
giant tuning slide with a mouthpiece and bell, allowing for effectively-
unhindered tuning flexibility akin to that of a chamber instrument or a human
voice.

~~~
zwieback
It was all too easy for me to adjust the tuning of any particular note on my
oboe, unfortunately usually in the wrong direction. The violin players in
front of me, who had much better pitch recognition than me, would shoot me
dirty looks and I'd get my pencil out to mark up the sheet music with arrows
pointing up or down.

~~~
yellowapple
Ah yes, forgot about oboe (and bassoon and English horn and double-reeds in
general), which tend to be much more sensitive about embouchure when it comes
to pitch if I remember right.

------
snorkel
For non-musicians, here's some terminology behind this:

There are 7 natural notes in (western) music: A, B, C, D, E, F, G (the white
keys on a piano keyboard)

... plus 5 accidental notes that half-way between: A#, C#, D#, F#, G# also
known as Bb, Db, Eb, Gb, Ab ... the black keys on a piano keyboard.

# means sharp (go up in pitch one-half step)

b means flat (go down in pitch one-half step)

7 naturals + 5 accidentals = 12 notes in the chromatic scale. These are the
primary colors in music.

Chords are like secondary colors. Chords are combinations notes that harmonize
well when played together. Typically chords are 3 or more notes spaced at one
note or one-and-half notes apart. So the C Major chord is C + E + G played
together.

Minor chords, noted with the lowercase "m" are made by dropping the "third"
note down a half-step, so "C minor" or "Cm" is C + Eb + G, can also be
expressed as C + D# + G

So put it all together, F#m means "F sharp minor" so the root note of the
chord is "F sharp" and the next note from the F major chord, A#, is dropped
down a half step from its major position to A natural, so the notes are F# + A
+ C#

Fortunately when playing an actual instrument you only memorize your finger
positions to make the entire common chord shapes rather than thinking about
the individual note under each finger.

The hook melody of song, the chord sequence that is repeated throughout the
verse or chorus, is expressed as chord progression in Roman numeral 1 to 7:

I II III IV V VI VII

Why did we switch from letters to numerals now? Because lettered notes A, B,
C, D, E, F, G are fixed positions (ie. hard-coded) and the numerals are
relative positions (ie. abstracted) So the Roman numeral expression is a more
general form of the melody structure. This lets you takes a progression like

C–G–Am–F (repeated over and over until you get a Grammy)

and expressed it as

I–V–vi–IV

.. which you can just shift up or down to another key and everybody loves your
new hit song, you win another Grammy, and few people realize it's same damn
song as before with new tempo and new lyrics!

[http://en.wikipedia.org/wiki/I%E2%80%93V%E2%80%93vi%E2%80%93...](http://en.wikipedia.org/wiki/I%E2%80%93V%E2%80%93vi%E2%80%93IV_progression)

...

~~~
codeulike
But the question is, what's natural about the Naturals, and whats accidental
about the Accidentals? Because taken together they are just 12 equally spaced
notes.

~~~
tajen
Harmonics. They resonate well together because they have some common
frequency. 13 equally spaced notes wouldn't match on multiples of 2, 3, 4 and
6.

Example: The major scale (C, D, E, F etc) are the notes 0/12, 2/12, 4, 5, 7, 9
and 11. You'd expect the 6th note to sound nice, wouldn't you? Wrong: The
scale is logarithmic.

A nice C chord is made of 0th, 4th, 7th/12, which are 523Hz, 659Hz, 783Hz.
Notice how the second frequency is 125% higher and the last 150% higher. So
they have harmonics in common and it makes them sound well together.

~~~
darkmighty
Yes (from the little I know) a major aspect in our hearing is that nature
doesn't produce pure sinusoids. Mechanical vibration materials is bound to
have a series of resonances multiples of some basic frequency. So if you have
a single person, or single object, emitting sound, you expect to see this nice
harmonic lineup. When the fundamental frequencies don't have a pair (a,b) s.t.
a * f1=b * f2, their harmonic multiples don't match and you can tell something
is odd.

For f2=125% f1, for example, every 4th harmonic from f2 lines up perfectly;
for f2=150% f1, every 2nd harmonic lines up; for f2= 200% f1, every harmonic
actually lines up. I guess it's like looking at combs with different spacings
and finding ones that superpose neatly.

------
cjslep
> Even though there is a great variety of chords and chord progressions,
> progressions involving 1,4,5, and 6 are favoured, probably because they
> ‘sound good’ to our brain.

I drive my girlfriend nuts because of this. I don't typically listen to the
pop/country songs that are popular with our local radio but when she has it on
in the car, every once in a while a song will come on and I'll think "I know
this" and start singing an older (wrong) song that fits the progression pretty
well.

~~~
ssharp
Do you really listen to the chords that closely? For a lot of music, the
chords are either largely hinted at (bass notes, the lead guitar or rhythm
guitar lick, and how the melody move) and if there is an instrument banging
out the exact chord progression, it's usually buried under the stuff or at
least the vocal.

If I'm writing a song, I'm spending almost all of my time doing things
tangential to the chord progressions, but rarely any time on the chord
progressions themselves. So usually I'll start with a guitar lick or vocal
melody, put a chord progression behind it, and then figure out the rest of the
arrangement.

If there's a song that's memorable to me, it's almost always because of the
main melody or guitar, not the underlying chords.

I'm only talking about pop-based music here, so rock, pop, country, etc.

~~~
cjslep
> Do you really listen to the chords that closely?

> I'm only talking about pop-based music here, so rock, pop, country, etc.

I rarely willingly listen to pop-based music. I don't consciously focus on the
chords that closely, but then again I haven't really thought that maybe how I
hear songs is different than another person (like the "do you see a duck or
rabbit" visual illusion, but with sounds).

For the really curious, the first album I really remember getting into as a
kid was Paul Van Dyk's Seven Ways album, which is a pretty minimal trance
album (compared to today's "edm") with very few vocals. At the same time, I
was getting into guitar with my cousins and playing instrumentals such as
Metallica's Orion or Call of Cthulhu. Also around that time my stepfather
entered my life. He played violin for a symphony and exposed me to the world
of classical music.

So while I've realized my musical tastes are strange (trance, heavy metal,
classical are still my go-to genres), I haven't really payed attention to how
I listen to music.

------
liminal
I created a similar visualization of part of HookTheory's data:

[http://briancort.com/songviz/](http://briancort.com/songviz/)

At the time they didn't have an API, so I emailed them and they sent me a
sample to work with. Would be interesting to see how it handles such a large
amount of data.

If you're interested in this sort of harmonic analysis, you might also like a
little visualization I created of the harmonies within a chord:

[http://briancort.com/chordviz/](http://briancort.com/chordviz/)

Great minds... ;)

~~~
datAmit
I'm the author of this article, and I signed up to ycombinator just to tell
you I can't get over your visualization. It's just friggin top. Any chance you
feel like explaining how you did it? mexindian@gmail.com

------
markbnj
To see how popular the 1-5-6-4 progression is you need only watch Axis of
Awesome ...
[https://www.youtube.com/watch?v=5pidokakU4I](https://www.youtube.com/watch?v=5pidokakU4I)

~~~
ljk
and before them:
[https://www.youtube.com/watch?v=JdxkVQy7QLM](https://www.youtube.com/watch?v=JdxkVQy7QLM)

~~~
aidenn0
Though Pachelbel's Canon is twice as long; it has a iii between the vi and the
IV, and a I IV V tacked on the end.

~~~
drostie
Right. You'll notice this in the Pachelbel rant; he very specifically only
sings "da, da-da-da, da-da da-da-da-da-da-da--" (the first half of the violin
theme) before abruptly cutting off because with this progression you
essentially only get the "first half" of the Canon.

------
m_eiman
Sounds like something that could be used to generate endless but still decent
elevator music with some Markov chains.

~~~
smrtinsert
It's funny, whenever I look up algorithmic music, it never seems to be the
usual pop cadences. The Phd who make this their field seem to prefer atonal or
dissonant generated music.

~~~
pierrec
The field of generative music is very under-researched, but there are some
great things out there, including tonal and "harmonious" ones.

Try David Cope:
[https://www.youtube.com/watch?v=CgG1HipAayU](https://www.youtube.com/watch?v=CgG1HipAayU)

And xoxos' "BreathCube" and "New Blend":
[http://www.xoxos.net/software/software.html](http://www.xoxos.net/software/software.html)

------
kowdermeister
"So for example, the transition 4->1->5->6 is one of the most popular ones"
The graph does not show this or I'm misunderstanding something. The most
popular looks like 1,4,1,5

Also, what does the double, triple numbers mean? 664, 66 in the fist column. I
know some music theory, but the article's explanation is rather confusing.

~~~
rspeer
He just said "one of the most popular", and 1 -> 5 -> 6 -> 4 is indeed the
ridiculously common progression of "four chord rock".

But if only the changes in chords are being notated, I bet 1, 4, 1, 5 comes
from the 12-bar blues, which is even more widespread than four-chord rock. The
12 bars that dominated the 20th century could be notated as:

1, 1, 1, 1, 4, 4, 1, 1, 5, 4, 1, 5

And if you only notate the transitions:

1 -> 4 -> 1 -> 5 -> 4 -> 1 -> 5

~~~
kowdermeister
Thanks, this makes sense, however the visuals did not really show the common 4
chord song pattern.

Anyways, I mostly produce electronic music and this blues progression just
gave me a good idea :)

------
protonfish
I am confused. Is "Start" always a 1? Then how can the first chord change also
be a 1?

~~~
stephen_g
Nope. 1 is the root (or tonic) of the key, not necessarily the first chord.

~~~
protonfish
Then what is the first chord? The beginning is labelled "Start" What does this
mean? Either less than 25% of songs start on the 1 (no way this is possible)
or the second chord is mislabeled as a chord change when it stays the same or
those with a 1 in the second column started on a chord other than the root and
instead of listing that chord, the data is thrown away. Something is messed up
here.

~~~
drostie
Why is there "no way this is possible"?

The 1 is the key, which is to say, the lowest note played in the progression.
If it's less than 25% then that means that 4-chord progressions frequently do
not choose their minimum as the first note.

~~~
protonfish
If you were a musician you'd know that in popular music the vast majority
start on the 1 chord. Classical music probably does this less frequently, but
it's nowhere around 1/5 of the time.

------
Reefersleep
This is great work. What I really want now is a version where you can listen
to the chords in the chart individually and in progression!

~~~
davec
Ask and you shall receive. Hooktheory's Trends tool lets you see and hear all
the chord progressions of the individual songs used here. As mentioned in the
article, this analysis actually used our free API for accessing our chord
progression database (I'm one of the creators of the site).

[http://www.hooktheory.com/trends](http://www.hooktheory.com/trends)

~~~
claar
Do you have to be signed in to see this feature? I can't find it. Neat site!

~~~
virusduck
When you select a progression, click on one of the songs.

------
tpoindex
Very nice presentation, although I'd prefer the graph settle to a steady state
a few iterations earlier.

Ob Lou Reed quote: "One chord is fine, two chords are pushing it. Three chords
and you're into jazz." ( [http://www.rollingstone.com/music/news/lou-reed-
velvet-under...](http://www.rollingstone.com/music/news/lou-reed-velvet-
underground-leader-and-rock-pioneer-dead-at-71-20131027) )

------
mwcampbell
Now I wonder if anyone has gathered data on vocal ranges. I'd love to be able
to query for a list of songs in my range.

------
joeyspn
Just learnt about [http://www.hooktheory.com/](http://www.hooktheory.com/)
thanks to this article, and I must say that I really love the concept of the
website. I've always had music production as a hobby but w/o proper music
theory background I struggled to analyse popular songs. This makes the process
really easy and fun!

I feel this site could be huge with a couple of tweaks: real-time and proper
midi interfacing. I hope the site will evolve towards more complex
collaborative songwriting...

------
wehadfun
Don't know the technical aspects of music enough to understand what is going
on here. Would like examples from real songs to illustrate.

~~~
yodsanklai
Most songs are based on chord progressions (a sequence of several chords) that
is repeated through the whole song. More precisely, there maybe different
chord progressions within a given song. For instance, one per section (intro,
verse, bridge, chorus, outro and so on...).

In theory, there are tons of possible chord progressions but not all of them
sound good. In practice some are extremely common (like I - IV - V in rock or
ii - V - I in jazz) and can be shared across very different genres. Google
"common chord progressions" for many examples.

Now for the numbering system. Chord progressions can be described as a
sequence of numbers that define the chords in a relative way (in CS terms,
think of a relative path in a file system VS an absolute path). In music, what
is important to the listener ear is the relation between the notes, not so
much the absolute pitch of those notes.

Example : A - D - E and E - A - B are the same progressions (I - IV - V) in
the key of A for the first one, and in the key of E for the second one.

Things get more complicated because you can have different quality of chords
(minor, major, dominant...) but you get the idea.

------
was8309
> ... how will humanity ever learn to be creative if everyone keeps doing the
> same thing over and over

this charted for the yearly top 100 selling songs over the last ~80 years
would clearly show the dumbing down of popular music. The Standard Songbook
contains music that everyday people sang and danced to, but has a creative
variety of chord progressions.

------
jader201
I'm a bit surprised that one of my favorite "poppy" progressions -- bVI bVII I
-- isn't more common. Or, is it that the database isn't very exhaustive yet?

[http://www.hooktheory.com/trends#node=b6.b7.1&key=rel](http://www.hooktheory.com/trends#node=b6.b7.1&key=rel)

------
ianremsen
For anyone rather confused, I wrote the majority of this wiki article on
introductory music theory.
[http://battleofthebits.org/lyceum/View/I+Am+New+To+Music+The...](http://battleofthebits.org/lyceum/View/I+Am+New+To+Music+Theory/)

------
indienkid
This is really fascinating. I'd be curious to know how different genres
compare, especially pop music.

------
lukas
This is a cool post. There's also a bunch of really interesting related
analysis on the excellent hookyheory blog
[http://www.hooktheory.com/blog/](http://www.hooktheory.com/blog/)

------
nathell
Somewhat relevant, The Million Song Dataset:
[http://labrosa.ee.columbia.edu/millionsong/](http://labrosa.ee.columbia.edu/millionsong/)

------
jay_neyer
Can someone please explain what the 646, b7, 36, and other numbers mean? They
discussed it briefly, but I didnt really follow. Sorry if its a noob question.
Looks great though!

------
Tloewald
Seems like you could take rap genius and this resource and combine them into a
Bayesian pop song generator. (Melodic and rhythmic progressions are the next
step).

------
bsder
Something doesn't look right.

How can such a small sliver go into flat6(b6) and yet a _much_ thicker sliver
flows out into flat7(b7)?

------
ljk
If this was done on the blues the chart might not be as diverse....

------
dharma1
forgot this
[https://www.youtube.com/watch?v=S4P8orKjadI](https://www.youtube.com/watch?v=S4P8orKjadI)

------
cbd1984
What is this magic chord they all start on?

------
circa
wow this is fantastic. captivating. I can't wait to go home and play now!

------
cbd1984
These diagrams make no sense.

