Can Major 7th chords be minor??

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Jonas
Posts: 8

Post by Jonas »

Hey!

just a quick question:
Can a one form a C minor chord as a major 7th chord (like Cm maj7) or is the major 7th chords reserved major chords only (and I shall choose minor 7th chords for minor's)???

Thanks
Jonas
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jimhenry
Posts: 1899

Post by jimhenry »

The short answer is YES. The preferred notation for such a chord based on a C root is Cmi(ma7) and it can be written out as a C minor/major seventh chord.

To delve a bit deeper, you can look at how the "legal" set of 7th chords is defined. You start by taking a diatonic scale, the usual 7 tone scale of western music. For example, C major--C, D, E, F, G, A, B.

Next, find a 7th chord by taking every other note, starting on each note of the scale:
CEGB
DFAC
EGBD
FACE
GBDF
ACEG
BDFA

Then figure out what each of those chords is by referring to the diatonic scale based on the root note of the chord. You have to look at the third (the second note of the chord) to figure out if the chord is major or minor.

CEGB All the notes are as they occur in the C major scale so this is a Cma7, or generically a Ima7.
DFAC The scale of D has 2 sharps, F and C. Therefore the F is flatted relative to the D major scale making it a minor third. The C is also flatted so it is a minor seventh. The chord is Dmi7, generically IImi7.
Moving more quickly through the remaining chords:
EGBD E has 4 sharps--F, C, G, D The chord is Emi7, IIImi7
FACE F has 1 flat--B The chord is Fma7, IVma7
GBDF G has 1 sharps--F The chord is G7, V7 (called the dominant 7th chord)
ACEG A has 3 sharps--F, C, G The chord is Ami7, VImi7
BDFA B has 5 sharps--F, C, G, D, A The chord is Bmi7(b5), VIImi7(b5)

Thus the native 7th chords to a diatonic major key are Ima7, IImi7, IIImi7, IVma7, V7, VImi7, VIImi7(b5) These seven 7th chords use only the notes of the diatonic major scale built on the root tone of the I chord. So the minor/major seventh chord does NOT occur by harmonizing a diatonic major scale.

However, if you harmonize the harmonic minor scale, which if built on a C root would be C D Eb F G Ab B, because in the harmonic minor scale you raise the seventh by a half step to creat a leading tone, a tone one-half step below the root. So B, which is flatted in the natural minor scale, becomes B natural, which is notated by a natural sign to overide the Bb in the key signature of 3 flats--Bb, Eb, Ab.

Now the chord built on C is C Eb G B, Cmi(ma7)!

This isn't used very much in pop or rock music. It is mostly a jazz chord. According to "Pocket Music Theory" the minor/mjor seventh chord almost always occurs between a minor triad and a minor seventh built on the same root:

Code: Select all

Cmi  Cmi(ma7) Cmi7
C    B        Bb
G    G        G
Eb   Eb       Eb
C    C        C
Note the descending C-B-Bb melody that is created at the top.

For more information see http://en.wikipedia.org/wiki/Minor_major_seventh_chord
Last edited by jimhenry on 11-05-12 5:24 pm, edited 1 time in total.
Jim Henry
Author of the Miditzer, a free virtual theatre pipe organ
http://www.Miditzer.org/
Jonas
Posts: 8

Post by Jonas »

Thanks, Jim Henry! :)

Just wondering, are u a piano teacher or an organ teacher or have u studied music theory? ;)
Based on your answer, it seems like you have a lot of knowlege! ;D


Tanks again
Jonas
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jimhenry
Posts: 1899

Post by jimhenry »

Studied music theory. I always wish my skill at music theory and skill at playing were reversed. It is annoying to understand what you need to play and not be able to do it. Synthesia is helping my playing get better but the more I play, the more I understand what the theory is about. :roll: It it is distracting to be thinking about what is going on from a theory stand point and lose track of what is supposed to be going on from a playing stand point. (Oh look! The left hand bounces from the tonic to the subdominant on the weak beat and then back to the tonic. Or at least that is what I should have done. :( That's called back cycling by the way.)
Jim Henry
Author of the Miditzer, a free virtual theatre pipe organ
http://www.Miditzer.org/
kiwi
Synthesia Donor
Posts: 1180

Post by kiwi »

jimhenry wrote:Studied music theory. I always wish my skill at music theory and skill at playing were reversed. It is annoying to understand what you need to play and not be able to do it. Synthesia is helping my playing get better but the more I play, the more I understand what the theory is about. :roll: It it is distracting to be thinking about what is going on from a theory stand point and lose track of what is supposed to be going on from a playing stand point. (Oh look! The left hand bounces from the tonic to the subdominant on the weak beat and then back to the tonic. Or at least that is what I should have done. :( That's called back cycling by the way.)
But u can still compose with theory even if u can't play it ^^
to merge theory on playabilty requiert more of playing than theory XD
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jimhenry
Posts: 1899

Post by jimhenry »

kiwi wrote:But u can still compose with theory even if u can't play it ^^
to merge theory on playabilty requiert more of playing than theory XD
Yes, I suppose one can compose even if one can't play. Modern tools for writing scores on the computer make that easier. I am not even convinced that being able to play is that much of a help in composing directly. The ways I can see playing help composition is that playing makes you more familiar with what others have composed and gives you a vocabulary of ideas that work and some idea of the correlation between how things look in a score and how they sound. Theory helps composition by giving you tools that suggest what is likely to work and what is likely not to. In the end, composition is about expressing your musical ideas. Neither playing nor theory will give you ideas standing alone but they can serve as a starting point for developing ideas.

For anyone who wants a little bit of a composition exercise here is a fairly simple challenge. Write 8 bars in F Major for piano based on the following chord progression:

||: F | F7 | Bb7 | Bbm | F7 Dm | G7 C7 | F | G7 : ||

The G7 in bar 8 is a turn-around and it should lead back to the F in the first bar. Extra credit for also writing an ending on F that replaces G7 in bar 8 the second time through. The chord progression is one that is used in at least some versions of the eight bar blues song "Don't Cry Baby." If you are new to this type of thing, just try to write a simple accompaniment type of pattern, not a solo. It could be whole and half note chords in the right hand and a quarter note arpegiated chord bass pattern in the left hand. This is what I've been working on for most of this week. If anyone takes up this challenge, please post what you come up with. It would be fun to compare notes (sorry for the pun).

To tie this back to the discussion, the above exercise is the kind of thing you can do based either on theory alone or playing ability alone. You can also do more interesting things if you have the talent to go beyond theory and things you've heard or played before.
Jim Henry
Author of the Miditzer, a free virtual theatre pipe organ
http://www.Miditzer.org/
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