Can someone explain musical chords to me?

What constitutes a chord? How many are there? Is there an infinite amount? I assume a chord would be the same for any instrument. Say a piano vs a guitar.
My apology if this belongs in the Cafe Society foruum.

I wouldn’t expect there to be an infinite number of chords. You can start by reading this Wiki page to get some basic understanding of chords.

In simplest terms, a chord is a set of musical notes that sound good together. “Together” can mean played all at once, or in succession, and of course “sound good” is subjective. In classical Western music theory, it most often refers to a set of three notes such that the ratios of the frequencies between the notes are (at least approximately) simple rational numbers.

For instance, if you play middle C, E, and G on a standard piano, with modern tuning, those notes will have frequencies of 523.25 Hz, 659.26 Hz, and 783.99 Hz respectively. If we re-scale those by the frequency of the C, we find ratios of 1, 1.2599, and 1.4983 . This is very close to 1, 5/4, and 3/2, simple rational numbers.

As to why we find notes with simple rational ratios pleasing together, it has to do with the fact that on most real instruments, a note is not just the fundamental frequency, but a set of overtones that are integer multiples of that fundamental frequency. So when you play that C on the piano, for instance, you’re not only getting 523.25 Hz, but also 1046.50 Hz, and 1569.75 Hz, and so on. Notes that have fundamentals in simple rational ratios will thus have a number of overtones in common.

In simplest terms, I’d say that a chord is a bunch of notes (generally at least three) that are sounded together (or in close proximity of time) irrespective of whether they sound good together. Originally, chords more or less all sounded good, but these days more or less anything goes.

As for whether they’re infinite, that depends on whether you are limiting it to a certain tuning system, and whether you are going to limit the allowable range. It’s a little silly to make chords out of notes that are outside of hearing range, but theoretically you can keep getting higher and higher notes, so you can keep adding chords (I suppose there is some upper limit, either in the material that is vibrating, or some kind of actual upper bound on frequencies; I’m not a physicist). If you’re going to allow playing around with tunings, then, sure, there are technically and infinite number of frequencies available, so you can make an infinite number of combinations out of them.

While there may not be an infinite number of chords one can play, taking into account all the different color tones one can add to a basic chord and the inversions, I certainly wouldn’t want to have to count them all.

If you really want to understand chords, we’d have to go into Music Theory, specifically scales, intervals, and inversions. Let’s not do that here. I’ll lay the basics on you and if that leaves you wanting to know more, ask and I’ll explain further.

At its most basic, a chord is 3 notes; the root, the 3rd, and the 5th. The root is the name of the chord. The note that is the root of a C chord is C. The 3rd is the 3rd note in the scale above the root. Depending on the scale, it can be 1½ steps (a minor 3rd) or 2 whole steps (a major 3rd) above the root. And the 5th is the 5th note in the scale above the root.

Note: on a piano, a “½ step” is the next note up or down on the keyboard. It doesn’t matter what color the key is. A “whole step” is the second key up or down. Again, color doesn’t matter. On a fretted string instrument like a guitar, a ½ step is up or down one fret. Or open string to first fret. A whole step is two frets up or down, or open string to 2nd fret.

The 3rd is a color tone. If the 3rd is a major 3rd above the root, then it’s a major chord. If it’s a minor 3rd, then it’s a minor chord. On top of that you can add either a major or minor 7th. You can add a 9th. You can add a minor 7th AND a 9th. There are even 11th chords. And there are 6th chords and ones with suspended 4ths. Frankly, I’m not really sure of the rules on whether you’re adding a 2nd or a 9th to a chord.

On a piano, playing chords is pretty straight forward; you hit the keys for the notes you want to play. Guitars are a bit different, especially if you’ll be strumming because you’ll be strumming all 6 strings (guitarists, I know, but please bear with me, I’m working on making a point), so you’ll be doubling some of the notes of a chord. For example, an E major chord is E G# B. If you’re strumming a basic E chord on a guitar, you’ll be playing EBEG#BE, so you’ve tripled the root, doubled the 5th, and played the 3rd once. On the basic G major, (G B D), you’d play GBDGBG, with a triple root, doubled 3rd, and single 5th.

And there are a variety of different fingerings/positions and variations of chords on guitar. And that’s all in standard tuning. There are non-standard tunings also with their own fingerings of chords. But no matter how the guitar is tuned and no matter what fingering you use, if you want to play an E major chord, you need at least one E, one G#, and one B.

Just to indicate how complex this business CAN be, let me start from a basic frinsance, a simple C chord. It is basically made of C, E, and G. (Three note chords are called triads) But which C, E, and G? Well, if all three of those notes are played simulateneously, they can be in any order and any distance away from one another. That is, a C is a C, so if you use the one near the bottom of the piano, or the one near the top, it’s still going to be a C chord, even though it may not sound anything like a different one. And, they can be in any order top to bottom. These are called inversions and they’re very important in the way music is written and sounds. Etc.

Moderator Action

Since this involves music theory it is best suited to Cafe Society.

Moving thread from General Questions to Cafe Society.

One issue with chords that ought to be addressed is how on solo instruments like piano, guitar, organ, accordion and such, the number of chords that can be played successfully will depend on the size of one’s hands.

When you move the area of consideration to bands, orchestras, choral groups and larger ensembles, the complexity and scope of chords can greatly exceed what an individual can play. The scores for symphonies, operas, concerti and Big Band arrangements can span the whole range of audible sounds, so even if the number of identifiable component notes isn’t really infinite, it could be a large number!

One of the first things you have to understand in music is called the octave. An octave is exactly double the frequency, and we call it an octave since in Western music we divide that range into 8 parts, which gives you the notes A, B, C, D, E, F, and G (and back to A again for the 8th step, in case you were wondering why there are only 7 letters). We further divide those with sharps and flats so that there ends up being 12 notes. Note however that this is only for Western style music, and other styles of music divide up the notes differently.

Even though how we divide the notes up varies from culture to culture, each way of doing it tends to follow certain patterns. Eastern music tends to have more notes per “octave” but they still divide it up on a per octave type of basis. The reason for that is that an octave, to our ears, sounds like the same note only higher or lower.

Other frequency patterns come into play as well. What we in western music call thirds and fifths (the 3rd and 5th notes of the scales respectively) also have simple frequency ratios (3:2 and 5:4). These frequency ratios sound pleasing to our ears (well really our brains, for reasons that scientists don’t fully understand) and combinations of these produce what are called the major chords. The minor chords also have a relatively simple frequency relationship (6:5).

One you start getting away from these simple frequency relationships, the combination of notes no longer sounds pleasing to our ears, so that limits the number of “chords” that are possible. Exactly how far away you can go is culturally dependent. Eastern music has semitones that are in between the notes of Western style music. This makes a lot of Eastern music sound weird to those in Western culture. On the other hand, the minor chords in Western music were historically once considered to be offensive to the ears. Over time they grew to be accepted and are now an integral part of Western music.

Different cultures will vary quite a bit in how they divide up their notes, but they all tend to at least start along the lines of these octaves and simple ratio chords.

With Western music, chords tend to be based around major and minor 3rds, 5ths, 7ths, and 9ths, and don’t tend to go much beyond that. There are however a lot of variations, even with just those few notes. A chord can start at the base note (called the fundamental, or root), or it could start at the 3rd and go up to the 5th and then the base note, etc. You can also have just the base and the 5th note (the so-called “power chord” used in rock music). Each instrument has its own limitations as well. Your fingers can only stretch so far apart on a piano keyboard, for example.

Most music can be played with only a handful of chords.

For example, this guitar chord chart only has 15 chords on it, and it’s enough to play a lot of the music out there:

This one, on the other hand, has 144 chords on it. There are a lot of guitarists out there who have never played a lot of the chords on this chart:

I don’t think that “officially” a chord has to consist of notes that sound good together. I have come across odd pairings of notes that really do sound off-to-quite-awful. But they’re played at the same time so they are chords.

In the parlance of music theory, a discipline that examines the structure of music, the word, chord, comes in handy. We have lots of great names and terms that can be applied to music’s components, including the aspect we call harmony. That’s where chords come in. Yes, there are plenty of combinations of tones that we can play, sometimes three at once, that sound good (or bad or something else), but if they don’t map to a large degree to some type of chord, we tend to call them tone clusters.

True: generally chords are built on thirds and fifths (although there is also the quartal chord, built on fourths). But there’s no requirement that they sound good: augmented triads and minor-major seventh chords, for instance, are not particular harmonious.

As someone who is proudly crap-to-mediocre on the guitar, I just want to stress this (in case the excellent posts so far in this thread has put anyone off from wanting to learn the guitar). You’ll mostly be playing the same handful of chords, until you either love them like an old pair or shoes, or you’re bored stiff by them.

(As we’ve learned, song writers aren’t actually all that original or imaginative. ;))

Another thing about chords on the guitar (I have no idea to what extent this applies to learning other instruments) is that, well, it’s not like you learn them all individually. This may be the most obvious point ever, but, you know, there’s a system.

When someone asks me how many chords I know on the guitar, I tell them: Five. A, C, D, E, G. Or that is, I know how to play the open chord shapes for those five chords, in standard tuning.

Well, that’s not exactly true. It’s just me being a bit disingenuous. In reality, there’s your major, minor, dominant seventh, major seventh, minor seventh, fifth, sixth, suspended second, suspended fourth chords. You have your nine, eleven and thirteen chords. You have your barre chords, your jazz chords, your power chords, your slash chords. Then there’s the any number of ways to add some random-ass notes to your chords, like with your dominant seventh sharp ninth chords or your major seventh flat five chords, et cetera, et cetera. There’s augmented chords and diminished chords. And your blah, blah, blah. And probably multiple fingerings for a lot of them.


Every chord you’ll ever play on a guitar will be related to a small set of basic ones. Chords with the same root note will usually “live” on the same area on your guitar. So, learn the five I mentioned, and everything else *will *make sense and fall into place. You get a feel for it pretty quick, and it even carries over into non-standard tunings and other less basic stuff.

And to put the guitar playing wannabees even more at ease: Learning a weird chord often doesn’t involve, well, learning the chord, or understanding how it works. You just learn how to play a particular song. The weird chord may be in there, but it’s not like you have to think about it, or know how it works in theory, any more than you need to know theoretical physics in order to play baseball.

In summary: There’s a reason why your stereotypical guitar player is someone who doesn’t know his music theory from a hole in the ground.

Guitar chords: Easy. It’s everything else (like making the damned thing sound good) that is the hard part.

I’m having a hard time finding the information content in this post. So far as I can tell, it’s something like:
1: The word “chord” means something.
2: The word “harmony” means something.
3: Whatever it is that “chord” and “harmony” mean, they’re related.
4: There’s also something else called a “tone cluster”, which is in some unspecified way different from those other things.

I have a friend that is a very accomplished guitarist. He writes his own stuff and one day he played me a piece that had a really nice chord progression that included a chord I couldn’t recognize while watching him play. I asked him what it was and he said, “I don’t know. Some kind of C I guess. Sounds great doesn’t it?”

I did find the chord later online but I was surprised to learn how constructing a song really works.

Chronos, my post is in response to the one immediately above it. If that doesn’t provide enough context, I’m sorry. Here’s another way of saying what I thought was perfectly clear. The word chord means something specific to people who know something about music. It’s not just a random collection of notes. So that if you’re discussing music in the conventional language of the field, (and I’ll presume the OP was asking for edification from people who know something about the field he’s curious about) saying any collection of tones is a chord just because they’re sounded together makes less precise and accurate the language of the discipline and renders the word, chord, less meaningful. What ftg was referring to is called a tone cluster. Is that any better?

I think that what CC means is that not all three (or more) note group are chords. For instance, I don’t think that anyone’d call C-C#-D or perhaps even C-D-E chords. They’re tone clusters for me. Chords at their most basic are formed by stacking thirds (or fourths in quartal harmony) and none of these groups fit that definition.

True. But CDE can be a voicing of a Cadd9, if you want. I find myself playing that cluster quite often as part of that chord, or CDEG. I have a very loose definition of chord: just any three or more different notes playing simultaneously (technically two would be called an “interval,” so “power chords” are really “power intervals,” but I’m willing to loosen up my definition even more to allow them, too.) For me, a cluster is a subset of a chord.

I see your point but I’m a bit unconfortable calling C-D-E a chord, especially if there’re played in the same octave. I’d like a G in there and perhaps have the notes more “spread out” if you see what I mean to really consider it a chord.

And this is exactly what I was referring to when I wrote, “… if they don’t map to a large degree to some type of chord we tend to call them tone clusters.” Keeping in mind that voicings and orchestrations and inversions all have something to do with the sound of notes played simultaneously, the most significant parts of a chord are the root - the basic tone of the chord, and the third - the tone that gives it it’s primary overall sound. Adding 7ths and 9ths give it a special flavor so that as pulkyamell says, a chord can be played without all its components, provided the ones that are included invoke the general overall sound of that chord, e.g. a 7th or 9th chord. In that example, a C, with an E above it, and a D above those will give the general impression of a dominant 9th chord or a C chord with an added 9th. If the C,D,and E are clustered together, they will tend to lose the sense of dominance and be interpreted more as a tone cluster.