| An interesting experiment is to ask people how many | | | | 6th/9th |
| chords there are in music. You'll be surprised to find out | | | | Add 2nd |
| that most musicians don't do any better at answering | | | | Add 4th |
| that question than non-musicians. | | | | Flat 5th |
| Why do you suppose is that? | | | | 7th with flat 5th |
| It is probably because it sounds like one of those | | | | That's 25 of the most-used types. There are several |
| questions such as "How many grains of sand on the | | | | other variations, but these chord types will do nicely for |
| seashore are there?", or "How many stars are there in | | | | our purposes of estimating the total number of chords. |
| the sky?" | | | | Each chord can be inverted -- turned upside down -- |
| And in a sense it is, but in another sense, we can get a | | | | by the number of notes in the chord. For example, a 3 |
| fairly accurate sense of chord population just by | | | | note chord has 3 positions -- root position, first |
| calculating all the chord types and then multiplying them | | | | inversion, and second inversion. A 4 note chord has 4 |
| by the number of inversions that are possible and the | | | | positions, a five note chord has 5 positions, and so on. |
| number of octaves that are possible on any given | | | | We will say for arguments sake that 4 positions is the |
| instrument. | | | | average, knowing that some chords have more and |
| So let's start with a listing of chord types: | | | | some have less. So if we multiply 25 chord types by 4 |
| Major | | | | positions, that gives us 100 possible chords per octave. |
| Minor | | | | But of course we can build chords not just on one |
| Diminished | | | | note, but on 12: C, Db or C#, E, F, F# or Gb, G, G# or |
| Augmented | | | | Ab, A, A# or Bb, and B -- 12 different roots. So 12 |
| Diminished 7th | | | | times the possible 100 or so chords per octave give us |
| Major 6th | | | | a rough total of 1200 possible chords. |
| Minor 6th | | | | Some instruments only have the range to play 2 or 3 |
| Major 7th | | | | octaves, whereas a piano with its 88 keys can play 7 |
| Minor 7th | | | | octaves -- 100 chords in the lowest octave, 100 chords |
| Half-diminished 7th | | | | in the next octave, 100 chords in the next octave, and |
| 9th | | | | so on up to the top octave of the keyboard. |
| Flat 9th | | | | So on the piano we could theoretically play those 1200 |
| Sharp 9th | | | | chords in all 7 octaves, giving us some 8400 possible |
| 11th | | | | chords. Of course, some would sound so low or so |
| Sharp 11th | | | | high that they wouldn't really be useable in a song. But |
| Suspension | | | | still, they are possible. |
| 13th | | | | So what's the answer to the original question? It |
| Sus 7th | | | | depends upon the instrument and how many variations |
| Aug 7th | | | | of each chord the individual musician uses -- but in any |
| 9th/Major 7th | | | | case, it's a bunch! |