The document introduces the dualo principle, a new notation system that displays notes on a staff based on their relative pitch relationships as intervals of thirds. It uses traditional musical staves but shows successive thirds rather than absolute pitch. This allows chords, scales, intervals and other elements to be represented with distinctive shapes. The dualo principle was conceived in 2007 and forms the basis for a new musical interface called the du-touch.

1. The dualo principle
by Jules Hotrique

2. The dualo principle
Foreword............................................................................................................ 3
The dualo principle...........................................................................................4
The chromatic dualo........................................................................................ 5
Notes...................................................................................................................6
Intervals.............................................................................................................. 7
Triads................................................................................................................... 8
Tetrachords........................................................................................................ 9
Scales................................................................................................................. 10
Figuring............................................................................................................. 11
Modes................................................................................................................12
2 Dualo, 2012

3. Foreword
The following booklet addresses musicians who already have notions of music
harmony.The notation used may be more familiar to jazz musicians than to classical
musicians, but the ideas that will be presented will be of interest to both.
The dualo principle is a concept that allows the musician to display the notes on a
fat surface. It is based on fundamentals of tonal harmony and is inspired from
African thumb piano.
This new notation of music uses traditional staves as a writing support with the
dualo key symbol : . But as opposed to indicating the absolute pitch of the notes,
it shows their relative pitch between one another. Thus, lines and interlines show a
succession of thirds. Many interesting harmonic properties result from this. I have
kept this booklet simple so you can discover this properties by yourself.
I imagined this new disposition of notes in 2007 after theoretical refexions. It is now
the basis of a new instrutment, the du-touch, manufactured and distributed by the
company Dualo. Do not hesitate to contact us at contact@dualo.org if you need
further explanations.
Jules Hotrique,August 2012
3 Dualo, 2012

4. The dualo principle
Odd degrees on one side, even degrees on the other side
two series of thirds in staggered rows
By default, the first degree, indicated by the dualo key, is on the right1
on
an interline, but it could really be represented on the left or on a line.
1 That is to say, played by the right hand forefinger, one finger for each degree.
4 Dualo, 2012

5. The chromatic dualo
a different direction for each type of third
major thirds go to the inside
minor thirds go to the outside
The use of the directions can be repeated everywhere on the keyboard
interface that can be seen as a 2 dimensions vectorial plan surface
generated by minor and major thirds.
5 Dualo, 2012

6. Notes
low pitches at the bottom, high pitches at the top
6 Dualo, 2012

7. Intervals
one interval, one vector
7 Dualo, 2012

8. Triads
one chord, one shape
M
major
m
minor
dim
diminished
aug
augmented
A triad is a three sound chord, that is to say a series of two thirds.
By default these shapes are to be realized by the right hand. For the left
hand, the shapes are symetrically opposite.
8 Dualo, 2012

9. Tetrachords
one tetrachord2
, a shape, a symbol
∆
maj7
-
min 7
x
7
ø
m7(b5)
±
min∆7
+
maj7(#5)
o
diminué 7
2 Four sound chords or series of consecutive thirds
9 Dualo, 2012

10. Scales
one scale, two tetrachords
extension
tetrachord
fundamental
tetrachord
Example in F major : = &
fundamental tetrachord : F maj7 → F - A - C - E,
secondary tetrachord : G min7 → G - Bb - D - F
10 Dualo, 2012
- ∆

11. Figuring
one scale, three caracter
11 Dualo, 2012
Key : C
Primary tetrachord
major 7
(C – E – G - B)
c ∆ -
Secondary
tetrachord : minor 7
(D – F – A - C)
Mode : major (∆-)

12. Modes
seven modes per family of modes.
∆
-
∆
-
ø
x
-
∆
∆
+
±
ø
o
x
-
∆
melodic major harmonic major
±
ø
x
-
ø
x
+
±
±
∆
-
ø
o
x
+
±
melodic minor harmonic minor
ex : minor harmonic mode : ±ø
4th mode of melodic minor (Bartok) : xx
12 Dualo, 2012

13. dualo.org
Dualo SAS – +33 9 50 52 62 32 – contact@dualo.org
Pépinière de la Courneuve – 1, Ccial laTour, 93120 La Courneuve
13 Dualo, 2012