Re: Chord (another digression)

[ah567@xxxxxxxxxxx (George W. Miklas)]

>
>Searched the archives without much luck (too much comes back with 'chord'
>:), and in my various pieces of Hohner propaganda I have seen pictures of
>the chord harmonica, but how on earth is it set up?  Looks like a bunch of
>4 hole sets, but what is the system? All I can gather is that there must be
>some maj7, min7, dom7 and maybe a dim or min7b5, but where are they?  How
>do they ascend/descend?  How many are there? George? Somebody?
>
>Regards,                  haandruss@xxxxxxx                  
>Harv                      *Opinions my own*
>

Dear Harv and Harp-L:

There are two styles of chord layouts which Hohner has produced though
the years +/- a couple of years is before and after 1940.  The "new"
chord is designed according to the circle of 5ths (from left to right).
It is two harmonicas, hinged together.  Each chord consists of 8 reeds.
There are 5 types of chords on the instrument:  major, minor, dominant
seventh, augmented and fully diminished seventh.  For every major
chord that you blow on the upper harmonica, you will draw its dominant
seventh.  For every minor chord that you blow on the bottom harmonica, 
you will draw either an augmented dominant, or a fully diminished seventh
dominant.  For example:

Upper blow:  C Major		G Maj	D Maj	A Maj	E Maj
Upper draw:  G Dominant 7th	D 7th	A 7th	E 7th	B 7th

Lower blow:  C Minor		G Min	D Min	A Min	E Min
Lower draw:  G Augmented	D Dim	A Aug	E Dim	E Dim

Now since each of the 6 augmented triads can function in 3 different keys, 
there are two duplicates and since each of the 6 diminished seventh chords 
function in 4 different keys, there are 3 duplicates.  For instance, above
might seem that I have made a mistake, an E dim below the E min, but it is
not a mistake.  You would expect a B dim in that position.  

The 6 diminished chords are Ab, Bb, C, D, E Gb.  Look at their spellings:

	PROPER SPELLINGS		ENHARMONIC SPELLINGS 	Duplicates
1.)	Ab dim:	Ab Cb  Ebb Gbb		Ab  B   D    F		1.)
2.)	Bb dim: Bb Db  Fb  Abb		Bb  Db  E    G		|   2.)
3.)	C  dim: C  Eb  Gb  Bbb		C   Eb  Gb   A		|   |   3.)
4.)	D  dim: D  F   Ab  Cb 		D   F   Ab   B		4.) |   |
5.)	E  dim: E  G   Bb  Db		E   G   Bb   Db		    5.) |
6.)	Gb dim: Gb Bbb Dbb Fbb		Gb  A   C    Eb		        6.)

Look at the similar notes in 1 & 4, 2 & 5, and 3 & 6.  Each of these chords
can function as though any one of its notes were the root.  

The 6 augmented chords are  A Bb Db Eb E G.  Look at their spellings:

	PROPER SPELLINGS		ENHARMONIC SPELLINGS    Duplicates
1.)	A  aug:  A   C#  E#		A   Db  F		1.)
2.)	Bb aug:  Bb  D   F#		Bb  D   Gb		|  2.)
3.)	Db aug:  Db  F   A		Db  F   A		3.)
4.) 	Eb aug:  Eb  G   B		Eb  G   B  			4.)
5.)   	E  aug:  E   G#  B#		E   G#  C 		        |   5.)
6.)    	G  aug:  G   B   D#		G   B   Eb                      6.)

As you can see, there are not as many direct duplicates here.

I am running out of time....I will tell more later!


--
George W. Miklas, bass harmonicist, Jerry Murad's Harmonicats

"Three G's and an Eb...who would think that these 4 notes would 
be the theme of a major symphoic work?"  Arthur G. Spiro, Ph.D.