Should the 7 in as dom7 chord be denoted as '7' or 'b7' ?

William Williamson

I think it's 7 or M7 - but then I am reminded of a diminished chord which I've heard described as a 'double flatted seventh' - which would only make sense if the 7 in a dom/min7 chord was a regular seventh was 'flat'.

octatonic

A△7 = A Major 7 = A C# E G# = R 3 5 7
A7 = A Dominant 7 = A C# E G = R  3 5 b7
Am7 = A Minor 7 = A C E G (You will also see it notated as A-7) = R b3 5 b7 
Am△7 - A minor, major7 = A C E G# = R b3 5 7 

You can call the interval between the Root and the 7th in a dominant chord either a minor 7th or a flat 7.
I find it is easier and simpler to use flat 7 because it removes the confusion between a minor 7th chord and a minor 7th interval.

paul_c2

7 on its own is a minor 7th. M7 is major 7. What do you mean by "dom/min7", its not clear. The problem with trying to clarify what the 7th is by putting, for example "C min7" is that because the 7 on its own doesn't need to be qualified as a minor 7th, the "min" used there (or lower case m) would be misinterpreted as the minor 3rd.

Half diminished 7th chord consists of R - m3 - d5 - m7 and its symbol is a circle with a line through it

Fully diminished 7th chord consists of R - m3 - d5 - d7 ie. the 7th is a diminished 7th, a semitone lower than a minor 7th and enharmonically equivalent to the major 6th. The symbol for a (fully) diminished 7th chord is a small circle with no line through it.

There's a bunch of alternate symbols for chord notation, for example a triangle can be used for a major chord, etc

Its inaccurate to describe a 7th (or any other note in a chord or scale) as "flat" because it depends what its flatter than. For example in G natural minor, the 7th is F natural but is a minor 7th. And if the scale had a diminished 7th in, that would be F flat (not double flat). Of course, a diminished 7th is always (by definition) a semitone flatter than a minor 7th, and a minor 7th is always (by definition) a semitone flatter than a major 7th. In theory the interval of an augmented 7th exists too, but it would be rarely seen and possibly considered confusing/wrong, even though its technically possible!

stratman3142

William Williamson said:

I think it's 7 or M7 - but then I am reminded of a diminished chord which I've heard described as a 'double flatted seventh' - which would only make sense if the 7 in a dom/min7 chord was a regular seventh was 'flat'.

By double flatted 7th do you mean the common way of playing a diminished chord which is 1, b3, b5, bb7 (or 6), which can be built on the (major) 7th note of the harmonic minor scale?

bingefeller

I'd just describe it as b7.

paul_c2

It can get confusing because in theory there's so many different kinds of 7th chord. If you put to one side oddities, there's 6 commonly found styles of the chord. If you include all the oddities, then there's about 54 different variations.....

William Williamson

Hi guys, Thank you all for the reponses and how to construct them - I just want to make sure I'm saying it correctly when I refer to the bolded note in the below chords:  A-C-E-G or G-Bb-D-F  .

@octatonic  has mentioned b3 and b7, while @paul_c2 has referred to them as m3 and m7 . Is there a consensus?

From what I can gather it would appear that "minor 7th" would be most appropriate, "flattened" or "b" being a function of notes rather than scale degrees (and by extension diminished 7th instead of double-flattened 7th? 

Is that about right? 

octatonic

William Williamson said:

Hi guys, Thank you all for the reponses and how to construct them - I just want to make sure I'm saying it correctly when I refer to the bolded note in the below chords:  A-C-E-G or G-Bb-D-F  .

@octatonic  has mentioned b3 and b7, while @paul_c2 has referred to them as m3 and m7 . Is there a consensus?

From what I can gather it would appear that "minor 7th" would be most appropriate, "flattened" or "b" being a function of notes rather than scale degrees (and by extension diminished 7th instead of double-flattened 7th? 

Is that about right? 

As I said above, you can use flat and minor fairly interchangeably.

Some interesting things that can crop up.

For instance Abm△7 has the notes Ab Cb Eb G. Cb is the minor 3rd (or flat 3rd), G is the major 7 (or just the 7th).
Ab7 (Ab dominant 7) has the notes Ab Cb Eb Gb. Cb is the minor 3rd (or flat 3rd), Gb is the flat 7 (or minor 7th interval).

paul_c2

I'd say that b7 isn't wrong but its open to misinterpretation depending on the key (signature) - also what would you call the major 7th in this style? Minor 7 is unambiguous, and m7 is almost there too (but on some electronic devices, or some people's handwriting, m might get confused with M).

I'd not use "double flattened" but use "diminished" instead, for similar reasons.

I guess, talking amongst guitarists 99% would know what you mean by b7 but amongst pianists or other instruments, they might interpret it as whatever note letter it is, but with a flat (especially a pianist who obviously sees the notes with accidentals easily, as the black notes). Also bear in mind that another musician might be "thinking" in another key signature, eg you could be in Bb and regard the b7 in that key as Ab, where an alto saxophone player would be thinking in the key of G and the minor7 would be F natural for him/her.