Forum: music.stackexchange.com
Tags: <chords><chord-theory>
Title: Are there any enharmonic chords?
Question: Will I even encounter any enharmonic chords? For example would an inverted variation of one chord be equivalent to the root variation of another chord?

Answers:
sents: text: Yes they exist.
text: I don't know all of them of the top of my head, but I'll give you the three that come to mind easily.
text: The first is a fully diminished chord.
text: Because there are only 12 named notes and a fully diminished chord is made of 4 notes that are a minor 3rd apart from each other (3 semitones) there are only 3 different chords but each can be named 4 different ways.
text: For example, a C fully diminished chord would consist of the notes C-Eb-Gb-Bbb , a Eb fully diminished chord would consist of the notes Eb-Gb-Bbb-Dbb(C) , a Gb fully diminished chord would consist of the notes Gb-Bbb-Dbb-Fbb(Eb) , and an A (Bbb) fully diminished chord would consist of the notes A(Bbb)-C-Eb-Gb .
text: The second is an augmented chord and like the fully diminished chord because there are only 12 named notes and
text: an augmented chord chord is made of 3 notes that are a major 3rd apart from each other (4 semitones) there are only 4 different chords but each can be named 3 different ways.
text: For example a C augmented chord would consist of the notes C-E-G# , an E augmented chord would consist of the notes E-G#-B#(C) , and a G# augmented chord would consist of the notes G#-B#-Dx(E) .
text: The third example are 7th and 6th chords.
text: Some minor 7th chords contain the same notes as 6th chords.
text: For example a C6 would contain the notes C-E-G-
text: A and an Am7 would contain the notes A-C-E-G .
text: In all these examples you name the chord based on the context of the key for example if you are in the key of Db minor
text: and you see the notes Eb, C, Gb, and Bbb
text: you would call that a C fully diminished chord because C is the leading tone of Db minor
text: so it makes the most sense in the key.
text: Another example is there are polychords and extensions that will contain the same notes.
text: A very simple example is Eb/C (produced Eb over C) can be represented as an C7#9.
text: While the notes of each are the same, a polychord refers to a specific idea where there are two distinct perceived chords rather then just one.
answer_details: author: music.stackexchange.com/users/7222/Dom
score: 21
sents: text: I will avoid the debate in the comments about whether "enharmonic" is the correct word.
text: But yes there are loads of examples of chords with the same notes in them.
text: Example 1 C D G =
text: Csus2 G C D = Gsus4 Example 2 A C E G = Am7 C E G A
text: = C6 Example 3,4
text: The full diminished and augmented chords where any one of the notes can be considered a root without even changing the type of harmony:
text: B D F Ab/G# (full diminished) C E ab/G# (augmented) Example in use and conclusion
text: The best name depends on context,
text: that is what chord it precedes and follows, more than it does on the inversion used.
text: The following (rather overused) chord progression I heard recently in a local band's song springs to mind: C Am F G
text: At the end of the song it went uptempo and the chord progression changed to the following: C6 Am7 F G
text: But the C6 and Am7 were exactly the SAME CHORD, completely blurred together.
text: EDIT:
text: John Lennon's Happy Christmas (War is Over) Just occured to me this is a good example of why you need different names for the same chord.
text: If we look at the chord progression over the first half of the verse, it's easy even for a non musician to appreciate the symmetry and realise why this song is so popular.
text: The fast change through chord type (3rd, sus2, sus4 and back to 3rd) combined with the slow change through chord root (A B E A) make this song both energising and soothing at the same time.
text: A Asus2 Asus4
text: A Bm Bsus2 Bsus4 Bm E Esus2 Esus4 E A Asus2 Asus4 A
text: Now, Esus4 and Asus2 contain the same notes.
text: If I wanted to standardise the name of this chord I could pick Asus2.
text: Applying this rigorously I get A Asus2 Dsus2
text: A Bm Bsus2 Esus2 Bm E Esus2 Asus2 E
text: A Asus2 Dsus2 A
text: Which is totally confusing and completely misses the point of the chord progression.
answer_details: author: music.stackexchange.com/users/9630/Level River St
score: 13
sents: text: There are chords that function in different ways in different contexts.
text: Take for example the chord C-E-G-A.
text: This is the tonic chord of the key of C major with an additional note.
text: It is called an "added-sixth" chord.
text: It has a very pleasing sound and is often used as an ending chord in jazz and in the music of Olivier Messiaen.
text: Now play C-E-G-A on your keyboard, but follow it with C-D-F#-A and then B-D-G.
text: As if by magic the chord has become the first inversion of the ii7 of G major; the "dominant seventh of the dominant seventh".
text: Same notes, but what was a restful ending chord is now a chord that has to move in order to resolve.
answer_details: author: music.stackexchange.com/users/113/Mark Lutton
score: 4
sents: text: I realize that this is in some sense the dual to what you asked, but here's one of the most famous chords in music history, the Tristan Chord .
text: 150 years after it was first played, still nobody can agree on how to interpret (and thus name) that chord.
answer_details: author: music.stackexchange.com/users/2212/Jörg W Mittag
score: 3
sents: text: Yes, for example the min9 is actually a maj13, 3 semitones away E.G. Gmin9 = BbMaj13 Very useful in jazz when you want to move somewhere other than the predictable (ii-V) patterns, e.g. if G wanted to move to C
text: it can now instead move to Eb (Bb being the 5th Eb as G is to C).
text: It's good to know and gives more options.
answer_details: author: music.stackexchange.com/users/63314/Paul Mina
score: 1

Summary of the answers:
There are many enharmonic chords.
Yes, there are many examples of chords that contain the same notes as each other.