COMMAND
nf – determine normal form for successive vertical sonorities in Humdrum inputs
SYNOPSIS
` nf [inputfile …] [> outputfile.nf]`
DESCRIPTION
The nf command is used to determine the normal form for any of five set-theory related inputs: pitch (semits), pitch-class (pc), prime form (pf), interval-class vector (iv), or Fortean set name (pcset).
"Normal form" is a standardized way of representing the pitch material for any arbitrary set of pitches. Normal form provides the most intervallically compact spelling of the pitch-classes evident in a given sonority. It is analogous to rearranging notes in a chord so that the spelling is in root position, close position, with duplicate pitch-classes eliminated. By way of example, a D major chord (in any inversion, with any spelling) will have the normal form: 2,6,9 — namely, the pitch-classes D, F#, A (as opposed to 6,9,2 or 2,9,6). See REFERENCES below.
When provided with semits or pc inputs, nf treats each input record as a set of pitches. Unisons and other pitch-class duplications have no effect on the output. Rests within a set of pitches are ignored; where an input record consists solely of one or more rests, a null-token is output.
The nf command is able to translate any of the representations listed below. For descriptions of the various input representations (including nf) refer to Section 2 (Representation Reference) of this reference manual.
It is recommended that output files produced using the nf command should be given names with the distinguishing `.nf' extension.
iv interval-class vector representation nf normal form representation pc pitch-class representation pcset Fortean pitch-class set name pf prime form representation semits equal-tempered semitones with respect to middle C=0 (e.g. 12 = C5) ———— ——————————————————————–
Input representations processed by nf.
OPTIONS
The nf command provides only a help option:
h displays a help screen summarizing the command syntax ——– ——————————————————-
Options are specified in the command line.
EXAMPLES
The following command outputs the normal form for the sets formed by
successive sonorities in the input file opus24
. The input may be
pitches, pitch-classes, Fortean set names, etc.
` nf opus24 > opus24.nf`
PORTABILITY
DOS 2.0 and up, with the MKS Toolkit. OS/2 with the MKS Toolkit. UNIX systems supporting the Korn shell or Bourne shell command interpreters, and revised awk (1985).
SEE ALSO
context (4), **iv (2), iv (4), **nf (2), **pc (2), pc (4), **pcset (2), pcset (4), **pf (2), pf (4), **semits (2), semits (4)
NOTE
The nf command is a shell script that invokes pcset -n
.
[]{#REFERENCES}
REFERENCES
Allen Forte, The Structure of Atonal Music. New Haven: Yale University Press, 1973.
John Rahn, Basic Atonal Theory. New York: Longman Inc., 1980.
Straus, J. Introduction to Post-Tonal Theory. Englewood Cliffs, N.J.: Prentice Hall, 1990.
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- Pertinent description in the Humdrum User Guide
- Index to Humdrum Commands
- Table for Contents for Humdrum User Guide
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