The Pitch space reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Pitch space

For people who check facts
In music pitch space is pitch relations, ie nearness or farness, represented through geometric models, most often multidimensional. Cognitive psychologistss including Longuet-Higgins (1978) and Shepard (1982), and composers and theorists including Weber (1824), Riemann, and Schoenberg (1954). There are generally at least two dimensions, one for pitch class and one for register (ie, the specific pitch). (Lerdahl, 1992)

Modulatory space is the pitch space within which modulation is possible. For twelve tone equal temperament, this includes only the twelve pitch classes.

The circle of fifths is one representation of pitch space, first proposed geometrically (see: Pythagoras) by Johann David Heinichen (1728), though he included the relative minor (thus the circle clockwise would read C, a, G, e...) (Lerdahl, 2001). The current major on the outside relative minor on the inside format was proposed by David Kellner (1737). M.W. Drobisch (1855) was the first to suggest a helix (ie the spiral of fifths) to represent octave equivalency and reoccurance (Lerdahl, 2001). Shepard (1982) uses a double helix of two wholetone scales over a circle of fifths which he calls the "melodic map" (Lerdahl, 2001). Michael Tenzer suggests its use for Balinese gamelan music since the octavess are not 2:1 and thus there is even less octave equivalency than in western tonal music (Tenzer, 2000).

Weber's "regional chart" centered on C major is:
d# F# f# A a C c
g# B b D d F f
c# E e G g Bb bb
f# A a C c Eb eb
b D d F f Ab ab
e G g Bb bb Db db
a C c Eb eb Gb gb

Lower case letters indicate minor key, uppercase major. This was first proposed by Vial (1767) (later Weber, Riemann, Schoenberg), the advantage over the circle of fifths being that it represents both relative and parallel major. (Lerdahl, 2001)

The use of a lattice was first proposed by Euler (1739) to model just intonation using an axis of perfect fifths and another of major thirds (Lerdahl, 2001). James Tenney argues for multidimensional lattices, especially for just intonation systems, which contain a dimension for every pitch axis used (Tenney, 1983). Thus if a justly tuned system is based on the octave and fifths it would contain only two dimensions. W. A. Mathieu uses this perfect fifths and major thirds also (Mathieu, 1997) (see sargam).

Riemann's Tonnetz:
A# — E# — B# — FX — CX — GX
| | | | | |
F# — C# — G# — D# — A# — E#
| | | | | |
D — A — E — B — F# — C#
| | | | | |
Bb — F — C — G — D — A
| | | | | |
Gb — Db — Ab — Eb — Bb — F
| | | | | |
Ebb — Bbb — Fb — Cb — Gb — Dbb

Perfect fifths are the horizontal axis, major thirds the vertical. First proposed by Euler, later used, not always in just intonation, by Hermann von Helmholtz (1863/1885), Arthur von Oettingen (1866), Renate Imag (1970), Longuet-Higgins (1962), Shepard (1982) "harmonic map"

Harry Partch's "Tonality Diamond" is similar:


3-limit just intonation


Deutsch and Feroe (1981), and Lerdahl and Jackendoff (1983) use a "reductional format" representing pitch relations by "alphabets" or hierarchy of levels such as the chromatic, diatonic, and triadic. Lerdahl's levels include the octave, perfect fifth, major triad, diatonic scale, and the chromatic scale:



Level a:
C











C


Level b:
C






G




C


Level c:
C



E


G




C


Level d:
C

D

E
F

G

A

B
C


Level e:
C
Db
D
Eb
E
F
F#
G
Ab
A
Bb
B
C



(Lerdahl, 1992)


		


Table of contents 







1 See also

2 External link

3 Sources




See also


External link


Sources