A triad is the most used set of notes making a chord. Obviously it's 3! However, there must be a word/ term for a set of 4 notes - as in maj 7th, or min 6th chord, and maybe a different one for a set of 5, as in a 9th chord. What is the term?

  • What's important is the function of the chord. Chords with many upper extensions can vary or be left out and still maintain their function, so I would usually be specific about the terminology and indicate the actual chord I wanted spelled out. That said, is there a context you are thinking of that such an explanation wouldn't cover?
    – mkingsbu
    Jul 17, 2015 at 13:26
  • @mkingsbu - I am aware of chord functions, and the fact that a P5 can be and is often left out of a chord. However, let's take a Cm7 as an example. Leave out the P5 and I don't believe it becomes a triad, per se. Just wanted to know of any nomenclature attached to 4 and 5 note chords. Since they are almost as commonly used as triads are.
    – Tim
    Jul 17, 2015 at 15:55
  • It is a really good question, I was just wondering if there was a context you were thinking of. In my case, I would imagine you could say, "Could you voice that chord as an 'x' instead of a 'y'?" Where x is a chord with 4 notes vs one with 3 notes. But in your example of a Cm7 I would specifically ask for the 5th to be included. Otherwise, a rhythm player may be interpreting that as to add more color tones and still omit the 5th!
    – mkingsbu
    Jul 17, 2015 at 16:15
  • 1
    @mkingsbu - a triad chord, played for example on guitar, I guess could contain up to 6 notes, but would be made up of only 3 note names: C maj = CEG. A tetrad (!) would have 4 different note names, with always the option of leaving out P5 - but why would one bother? The omission of P5 is more often to accommodate more extension notes, especially on gtr. where fingerings soon become impossible, as I think you hint at. If the written chord is Cm7, then that's what I would expect to play, probably with all 4 note names inc. On occasions, I'd maybe make it a Cm9 - and check for grimaces...
    – Tim
    Jul 17, 2015 at 16:34

3 Answers 3


The name is indeed tetrad, as pointed out in a comment by Shevliaskovic. However, this term is not very common. Standard tetrads built in thirds are almost always referred to as seventh-chords. The problem is that there are two common four-part chords (yes, that's actually a very good name!) that are no seventh chords, because they contain a major sixth instead: X6, Xm6 (replace X with any root you like). They can be referred to as sixth chords, but traditionally they would be called added tone chords, or, more specifically, added sixth chords.

In sum, for chords arranged in thirds, the most common names are seventh-chords, ninth-chords, eleventh-chords, etc. Chords consisting of a triad and other added tones (not in thirds) can be referred to as "added tone chords", or if you want to be more specific, as "added Xth chord", where X specifies the added scale degree (such as a sixth). For chords with more general structures I think that "N-part chord" (N=4,5,...) is the clearest and most common name.

I believe that the terms "pentad" (etc.) are not at all common in music theory. There exist terms like pentachord and hexachord, but they do not necessarily refer to chords but to series of five or six notes.

  • I think your term of 7th, 9th, alt. chords is about as close as you can get. Unless one is talking about serialism, in which case the tetrachord, pentachord, and hexachord, dodecachords, etc. have unique functionalities that are not related to conventional functional, or even non-functional harmony like the blues.
    – mkingsbu
    Jul 17, 2015 at 16:21

the word triad is not specific to music and simply means a group of three. In general the series is, monad, diad, triad, tetrad, pentad, hexad, heptad etc.

Check out this list of polygon names (http://mathcentral.uregina.ca/qq/database/QQ.09.96/rosa1.html) I'm reasonably sure you can just replace the letters "agon" with "ad" should you ever need more than seven notes in a chord.


There's no generally used name beyond dyad (2) and triad (3) (some would dispute that a dyad deserves the label 'chord', but that's a different question.)

Note that although we have a chord naming system (mostly) based on a 'pile of thirds' - triads, sevenths, ninths etc. - many three-note chords are not triads, many 4-note ones are not sevenths... And there are many possible chords that don't fall into our 'chord symbol' naming system at all.

enter image description here


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.