Q: What is a chord harmonica?
A: As an extension of the more general discussion in part 1 and from “Re:
Chord (another digression)” 30 Aug 1994 GM:
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 — “Re: Chord
(another digression)” 30 Aug 1994 GM
Also from “Chord and Bass Layouts” 30 Aug 94 WY:
The chord has a two-tiered layout with hinge, like the bass. It
is also an octave-tuned double reeded instrument, but it has both
blow and draw notes, which produce different chords. The chords
are arranged in the cycle of fifths (they used to be different,
but I don’t know the details. While watching Al Smith and Alan
Pogson both playing chord on-stage together at the SPAH
convention, they kept moving their instruments in opposite
directions. I thought maybe one guy played upside down, but it
turned out they had different vintage instruments with different
chord layouts).
Here is the current (I think) layout for the chord:
BLOW Gb Db Ab Eb Bb F C G D A E B
TOP
DRAW Db7 Ab7 Eb7 Bb7 F7 C7 G7 D7 A7 E7 B7 F#7
BLOW Gbm Dbm Abm Ebm Bbm Fm Cm Gm Dm Am Em Bm
BOTTOM
DRAW Db+ Ab@7 Eb+ Bb@7 Bb+ C@7 G+ D@7 A+ E@7 E+ F#@7
In the top row the draw and blow chord in each location form a V7
and I relationship, just like on the lower part of a diatonic.
In the bottom row, we have minor chords instead of major,
with the same chord roots, so you could still play a V7 – I by
drawing and blowing in the same horizontal location, but you
would have to switch rows to get the minor chord.
The draw chords in the bottom row alternate between augmented (+)
chords and diminished 7ths (@7), with the same chord roots as the
draw chords on the upper row. Augmented chords often are used as
a different color of V chord, so they’re fairly well placed as
draw chords. The diminished are a little more tricky, and very
versatile (I won’t get into that now).
Now, we have twelve of every other kind of chord, but only six
each of augmented and diminished. But there are really only four
unique augmented triads, and only three diminished sevenths, if
you discount duplicate spellings (C-Eb-Gb-Bbb = A-C-Eb-Gb, for
instance, and G-B-D# = Eb-G-B). So actually having six of each
gives us some duplications to work with (A+ = Db+, Eb+ = G+)
(Ab@7 = D@7, Bb@7 = E@7, C@7 = F#@7).
Some chord players block out notes to alter chords, and some have
mastered the art of playing two chords, or parts of two chords,
together to create a more complex chord.
All kinds of tonguing effects are also possible. — “Chord and Bass Layouts
” 30 Aug 94 WY, “Re: Chord and Bass Layouts” 31 Aug 1994 GM
