# Building the chords for C#m(b6)

Hello i'm new to music theory and im trying to apply basic scale theory to form the chord mentioned above but it im not getting the notes required to form the chord.

This is what i did. C#m is the relative minor of E major, so the scale starts with the sixth degree of the major scale which gives C#,D#,E,F#,G#,A,B,C# as the natural minor scale. So C#,E,G# gives the chord for C#m. But for C#mb6?? C#,E,G#,Ab ??? Its for the flat sixth that i don't understand.

Where on Earth did C#m(b6) come from? It's not a common chord - in fact, I've never ever used it, or seen it on music.

You're right, that C#m is spelled C# E G#. The 6th note will always be the major 6th note, of A#, spelling C#m6 as C# E G# A#. However, the chord you ask about is supposed to have that 6th flattened, making it an A. So now you have C# E G# A, which is an inversion of Amaj7, the first inversion, sometimes labelled Amaj7/C#. Although with the G# and A that close on top, it doesn't sound too good in close harmony.

I don't believe it's from a song, and if it is, the writer has made a fundamental mistake, and it is actually Amaj7.

From your comment to Matt, no, a beginner wouldn't realise that. A beginner also wouldn't realise that some chords don't get named in the way this 'chord' has.

• @Stretto - thanks for the comment, but not a lot of it makes sense to me. Very common - no. Maj6 is the Dorian form? OP is asking about m6. I play all sorts, including jazz, where I might have met this mythical chord, but no. Treating the vi as a ii? vi is C#m(6) and ii is F#m, so poles apart. Help, please, I don't understand - and I need to!
– Tim
Sep 11, 2017 at 10:12
• Im totally lost, i have no idea what you guys are talking about haha.....dorian...Treating vi chord as ii...total alien language to me haha Sep 11, 2017 at 10:46
• While I definitely agree that you will likely never find this chord in the wild, I can't say that I would agree that this absolutely has to be called Amaj7. Depending on who wrote the chart and its context, it might make sense. Incredibly unlikely but possible. It's probably not worth the time for a beginner to put too much thought into it as anything more than learning what notes to play for a chord symbol. Sep 11, 2017 at 19:47
• I'd suggest that the statement "...with the G# and A that close on top, it doesn't sound too good in close harmony" is an opinion rather than a fact. Sep 12, 2017 at 12:33
• @BrianTHOMAS - true, and I believe that the majority would agree. Most of the time when I see and play stuff that has two notes that could be a semitone apart, they're separated in order to 'not sound too good' otherwise.
– Tim
Sep 12, 2017 at 13:49

TL;DR: The numbers within a chord symbol and their associated alterations (# or b) can be determined by comparing them to the Mixolydian mode.

One point that seems to be missing from the otherwise good answers, when you see most chord notation, you will see that most notes beyond the triad that are specified (2, 4, 6, 7, 9, 11, 13) will be based on the note within a major scale context, so when a flat is added before it, you are lowering it from what would appear in a major scale. The exception is for a dominant 7 chord, where 7 on its own is b7.

Let's look at this in the keys of C major and C minor in terms of scale degrees:

C Major

• C: 1
• D: 2/9
• E: 3
• F: 4/11
• G: 5
• A: 6/13
• B: Major 7

All of these notes could be describe as either Major (2, 3, 6, 7) or Perfect (1, 4, 5) but the only one that we need to make this distinction for is the 7, otherwise it is implied. (In case you're not aware, 9, 11, and 13 are essentially synonymous with 2, 4, and 6, though they do function somewhat differently)

C Minor

• C: 1
• D: 2/9
• Eb: b3
• F: 4/11
• G: 5
• Ab: b6/b13
• Bb: b7

Notice how 2, 4, and 5 are all the same as the parallel major (C major). These intervals are still Major or Perfect, even in a minor key. We would usually make the distinction of the others as being flat because we are comparing them to the major scale.

You can also # chord tones/scale degrees but this is mostly limited to 4 and 5 until you get to more advanced theoretical concepts. So the occurrence of #4 and #5 is relatively common. I'd also note that b4 is not really a thing outside of advanced theory and even there it is still very uncommon.

In the context of speaking about chords, the numbers that we reference are based either on those of the major scale, or the one exception of the 7 being a dominant 7 (b7). I believe the reason that the 7 is the exception here is that earlier music didn't tend to use major 7 or minor 7 chords, primarily just dominant 7 chords (some diminished as well). Since dominant 7 chords came into common use first, as well as still being the most prevalent type of 7 chord, they get the use of the implied meaning.

Context is important here, though. When we speak of a chord and have already declared the type of chord, we usually don't specify the chord tone's quality, or at least we don't need to, since it is implied by the chord name itself. Fro example, on a minor chord, where everyone is aware that I'm speaking about a minor chord, I don't have to say b3, I can just say 3, because all who have studied theory know by definition that a minor chord has a b3.

So what we are trying to understand here, is how and why certain chord tones are specified within the chord symbol. The implication of any number will be either major or perfect, except the 7, unless otherwise stated. So a C chord will be major and we would have to specify that a C minor is a minor chord in the symbol (C min). C7 is dominant but if we want a major 7 chord, we would need to specify that in the symbol (C maj7). For a minor 7 chord (C min7 or C-7), we just need to state that the chord itself is minor (as opposed to specifying that the chord itself is minor and that the 7 is flat) and the understanding is that the 7 will be a flat 7, as that is far and away the most common type of minor 7 chord. Extending this logic to the remaining notes, we need to specify what they are only if they differ from the major scale.

The chord symbol that you've brought, C#min(b6), should be a minor triad with a b6, which would be a minor 6 interval from the root, which is A in this chord. They specify b6 because saying 6 would imply a major 6, which others have mentioned is found in the Dorian mode.

As others have mentioned, this is a very uncommon chord, however, it is possible and you've found it. The purpose of theory is to explain music and provide a language. Depending on what you're looking at, there can be many interpretations and we can't necessarily say one or the other is more correct. Others have mentioned that this could be a first inversion A maj7 chord (A maj7/C#), which would describe the same notes but I can't objectively say which would be a better descriptor without context. If this was one in a series of chords, such as C# min7, C# min6, C# min(b6), then it would make more sense. If it was one in a series of another progression, such as A maj7, C# min(b6), A maj7/E, then it would make more sense to call it A maj7/C#. There are situations where I've seen chords described in ways that seem ridiculous to me, such as G/E, which is really just an E-7 chord, however, that symbol may make more sense to one person than E-7 would and being that they contain the same notes, I can't objectively say that G/E is wrong, though it does not line up with the conventions that musicians use, so I would never choose to describe it as such, other than possibly in a pedagogical setting.

In reality, I could have described all of this in terms of the Mixolydian scale. Mixolydian is the same as the major scale but with a b7, which was the one exception I described. I chose to go from major because of how you framed the question but if you understand the Mixolydian scale, it would be easier to think of it that way. So when you see a chord symbol, you can compare the specified numbers with Mixolydian to determine what notes they should be. Eventually most of this should become obvious and automatic for you, since this is all fairly standard within just about every approach to theory in the western music tradition. Extended chords in a Classical setting are definitely an exception but it's unlikely that most reading this would need to know much about that unless they are in an academic setting, where it should be spelled out fairly clearly for them anyhow.

• Thanks, I really thought of framing this against the Mixolydian scale after having written most of the answer and considered changing the answer before posting until I thought of how the OP asked and what would provide an easier context for their understanding and based on another comment, they didn't know Dorian, so Mixolydian didn't seem a likely part of their vocabulary. Sep 11, 2017 at 20:35

A minor sixth up from C# is an A, so the chord would be `C# E G# A`, which is just an inversion of an A major 7th chord (`A C# E G#`).

Note that a C#m6 chord (without the flat) would have an A# because '6' refers to a major sixth. This latter chord is actually much more common than the chord you ask about.

• So without the flat C#m6 would be an inversion of A major augmented 7th? Sep 11, 2017 at 8:54
• Thank you for your answer but this doesnt really help me understand how to build the chord. How should a beginner realise that the inversion of A major 7th gives C#mb6? Sep 11, 2017 at 9:07
• @Raynezick: The b6 of C# is A, so that's how you get your chord. Not sure what you don't understand. And without the flat a C#m6 is equivalent to an A#m7(b5) (A# half-diminished). Sep 11, 2017 at 10:23
• Augmented 7ths are quite rare, as they end up as the octave in sound, but with very little reason to be called aug7, rather than plain and simple octave. You should call it 'Amaj7', as that's what the notes actually make in 99% of music. The fact that it has C# as the bottom note doesn't necessarily mean the name has to be changed to a chord starting with that note.
– Tim
Sep 11, 2017 at 16:32
• Whenever you see a chord symbol that says aug7, the chord is an augmented triad with a b7. I've never actually seen anyone talk about an augmented 7th degree/chord tone. I have heard of a b15 though, which seems similarly arbitrary. Sep 11, 2017 at 19:40