Look at how aesthetically pleasing that is (Click here for extreme closeup!)
I put together this chord chart to share on Reddit and I am quite proud of it, so I thought I'd share it here too. Fair Warning: this will probably be a very boring/confusing read if you aren't a musician.
Chords are what make the guitar an interesting instrument. There are two kinds of instruments: 1-note instruments and many-note instruments. Guitar is nice because you can play 6 notes at once if you want (or more if you're weird like that). Here's how to make sense of guitar chords.
Chords usually stay in a key
Whenever you hear a relatively simple song, the musician will usually stay in the same key. Each key is a scale of 7 notes and for each scale, there is a set of 7 chords which only contain the notes of the scale. My chart is organized so that each row is a different key and I have all 7 chords there for easy access.
Take the key of G. The G scale is G-A-B-C-D-E-F#-G (7 notes plus the octave). The chords in the key of G are G (G-B-D), Am (A-C-E), Bm (B-D-F#), etc. If you look at all the chords in the key of G, they only contain notes in the G scale.
If you were strumming along in the key of G and decided to play an E chord (E-G#-B), it would sound weird since G# is not in the key of G. You'd be able to tell that something was different. Anybody that listens to music semi-regularly would notice this because our ears are used to hearing chords that stay in the key. There are ways of using out-of-key chords, but generally a simple song will stay in the same key. Particularly in church. If the band is playing in one key and decides to switch to another key, it is hard to get everyone in the building to follow, so most worship songs try to stay in the same key.
What is a key?
A key does not only tell you how many sharps or flats are in the scale. It also tells you what chord the song resolves on. This may mean that the song starts and/or ends on a specific chord, but the song will not necessarily start or end on the 1st chord of the key (the tonic). It simply resolves on that chord.
A song that I wrote contains the chord progression C-G-D-Em-C-G-D in the verse and Em-C-G-D in the chorus. Looking at all the chords in the song and comparing it with my chord chart, you would know that it is either in G major or E minor. To me, it can be somewhat ambiguous as to whether a song is in a major key or its minor key counterpart. But if you heard the song, you would hear that the verse has a G "major" feel, but the chorus has an E "minor" feel. The verse doesn't start or end on D, but if you heard that last D in the progression, you would naturally feel like a G chord would resolve it nicely. The chorus is a bit more obvious about it resolving on the Em since the progression starts on the Em.
Steps in a Scale
This chart is a periodic table of sorts. Each column represents a specific step in the key. The steps are I-ii-iii-IV-V-vi-vii° (same thing as do re mi fa so la ti (do)). Uppercase means it's a major chord, lower case means it's a minor chord, and lower case with a ° sign means it's a diminished chord. Every major key has the same set of steps. So in any key the first (I), fourth (IV), and fifth (V) are always major chords and the same goes for the minor chords and diminished chords. What this means, is that I can play my C-G-D-Em (IV-I-V-vi) progression in the key of G and it will sound incredibly similar to the progression F-C-G-Am (IV-I-V-vi) in the key of C. All the pitches will just be equally shifted to higher notes.
Practically speaking, this is very useful when you encounter a song that's in a horrible key like Eb. If you play guitar, you know that Eb-Fm-Gm-Ab-Bb-Cm-Ddim aren't exactly fun chords. I'd much rather play in the key of D. So, what you can do is capo the first fret since Eb is a half step higher than D and then change all the "I" chords in Eb to the "I" chords in D, all the"vi" chords in Eb to the "vi" chords in D, etc. Once you do this, you can comfortably play with a capo in the key of D while everybody else is playing in Eb.
Circle of Fifths
Now there is a very good reason why I organized the rows the way I did. When I first saw this chart it was organized ABCDEFG and it totally frustrated me that it was organized that way. To a musician, it makes much more sense to organize different keys according to the Circle of Fifths.
The circle of fifths is organized according to fifths (big surprise). So the fifth of C is G, the fifth of G is D, the fifth of D is A, etc. This is useful for a few reasons. One is that you can look at any key in the circle and know the 6 minor and major chords in that key. Every key has 3 major chords and 3 minor chords. So if you look at C, you see that the chords F and G are the other major chords and the chords Dm, Am, and Em are the minor chords. Then you just have to know that the 7th of the key is going to be the diminished chord of the key, but those of us who are lazy rarely use diminished chords anyway. Another handy thing about the circle of fifths is that as you go around the circle, you add or subtract a sharp or flat, which you can see in my chord chart. Because of this, neighbors in the circle share 6 common notes. Because they share so many notes, it is easiest to modulate between neighboring keys in the circle. A music major, or somebody who paid more attention in music theory than me, might be able to tell you more reasons the circle of fifths is amazing, but these are all the reasons I know.
So there you have it. My guitar chord chart. If you click here, it gets nice and big and mostly printable.
