interval quality question
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- KVRist
- Topic Starter
- 70 posts since 24 May, 2021
can you all indulge me with another Music Theory 1 question.
I am looking at Major scale 7th chords...And let's take the Key of C, and the 7th scale.
so we have notes, B, D, F and A to make up the 7th chord. BDF is a diminished triad since intervals are a minor 3rd stacked on top of a minor. But when we add A on top of F, we are adding a Major third.
My book says the quality of the 7th is a minor and that this chord is called a diminished minor 7th, or a half-diminished 7th...I don't care what the chord is called, but I don't understand why they are saying the quality of the 7th is a 'minor;
can anyone help ?
I am looking at Major scale 7th chords...And let's take the Key of C, and the 7th scale.
so we have notes, B, D, F and A to make up the 7th chord. BDF is a diminished triad since intervals are a minor 3rd stacked on top of a minor. But when we add A on top of F, we are adding a Major third.
My book says the quality of the 7th is a minor and that this chord is called a diminished minor 7th, or a half-diminished 7th...I don't care what the chord is called, but I don't understand why they are saying the quality of the 7th is a 'minor;
can anyone help ?
- KVRAF
- 11093 posts since 16 Mar, 2003 from Porto - Portugal
That chord is the leading tone seventh chord, because it is built over the leading tone (the seventh degree of the scale). It only exists in Major mode (major scales). Although it has a diminished fifth, the seventh is, in fact, a minor seventh.shugs wrote: ↑Tue Nov 30, 2021 1:53 pm can you all indulge me with another Music Theory 1 question.
I am looking at Major scale 7th chords...And let's take the Key of C, and the 7th scale.
so we have notes, B, D, F and A to make up the 7th chord. BDF is a diminished triad since intervals are a minor 3rd stacked on top of a minor. But when we add A on top of F, we are adding a Major third.
My book says the quality of the 7th is a minor and that this chord is called a diminished minor 7th, or a half-diminished 7th...I don't care what the chord is called, but I don't understand why they are saying the quality of the 7th is a 'minor;
can anyone help ?
In minor mode scales that chord is a diminished seventh chord, and it is also built over the leading tone (the raised seventh degree of the scale). The leading tone in a minor mode is a raised tone. That raised tone will form a diminished seventh with the sixth degree, which is the seventh of the chord.
To sum it up the leading tone seventh chord belongs to Major. The diminished seventh chord belongs to minor. Both are built over the leading tone (seventh degree) which, in minor, is raised (otherwise it would not be a leading tone).
Last edited by fmr on Tue Nov 30, 2021 5:53 pm, edited 2 times in total.
Fernando (FMR)
- KVRist
- 392 posts since 4 Aug, 2020 from Montreal, Canada
- KVRist
- 392 posts since 4 Aug, 2020 from Montreal, Canada
...
Anyways, the names of chords are something you have to know because they reflect their distinctive sonic signatures. Calling a 7th chord "major" or "minor" quality is way too vague (if not bullshit).
In the key of C, we have CMaj7 Dm7 Em7 FMaj7 G7 Am7 Bm7b5.
The G7 and Bm7b5 are just unique ones, as their names suggest.
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- KVRist
- Topic Starter
- 70 posts since 24 May, 2021
I understand memorization, And I am not talking about the naming of the chord.
I am trying to get at the 'why' they are saying the QUALITY of the 7th is a minor....Usually naming something has some logic behind it and I cannot fathom this one
I am trying to get at the 'why' they are saying the QUALITY of the 7th is a minor....Usually naming something has some logic behind it and I cannot fathom this one
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- KVRist
- Topic Starter
- 70 posts since 24 May, 2021
The quality of the 7th is minor when we had a minor third and the quality of the 7th is major, when we add a major third EXCEPT when we add a major third to the diminished 7th triad in a Major scale. There is a reason ( I assume)
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- KVRist
- Topic Starter
- 70 posts since 24 May, 2021
Actually, I think I just figured it out.....They are looking at the quality of the interval from the root to the 7th and saying that is the quality.....Now it makes sense
- KVRAF
- 11093 posts since 16 Mar, 2003 from Porto - Portugal
They say the 7th is minor BECAUSE THE 7th "IS MINOR". What's so difficult in there? For the chord to be called a diminished 7h, it must have a diminished 7th.
Last edited by fmr on Tue Nov 30, 2021 5:52 pm, edited 1 time in total.
Fernando (FMR)
- KVRAF
- 11093 posts since 16 Mar, 2003 from Porto - Portugal
- KVRAF
- 25053 posts since 20 Oct, 2007 from gonesville
back to where you didn't care about 'diminished/minor 7th' (note the slash): the first bit there is the quality of the triad, then the quality of the seventh. This is the common practice nomenclature.
in major: I7 is major/major; ii7 is minor/minor; iii, 7 minor/minor; IV, major/major; V, major/minor, vi, minor/minor; vii diminished/minor.
In minor with an harmonic focus, ie., a raised 7/leading tone, vii is diminished/diminished, a diminished seventh chord (as opposed to half-diminished 7th on vii in major; & the ii in minor is a dim/minor, eg., Dø7 in C minor.
in major: I7 is major/major; ii7 is minor/minor; iii, 7 minor/minor; IV, major/major; V, major/minor, vi, minor/minor; vii diminished/minor.
In minor with an harmonic focus, ie., a raised 7/leading tone, vii is diminished/diminished, a diminished seventh chord (as opposed to half-diminished 7th on vii in major; & the ii in minor is a dim/minor, eg., Dø7 in C minor.