Theory Resources

This page lists the common transposing instruments in the orchestra, and their transpositions.

This webpage lets you enter pitch collections, and looks for possible ‘Pressing scales’ (a term coined by Dmitri Tymoczko in his article Scale Networks and Debussy).

The seven possible Pressing scale collections are: DIA (Diatonic), ACOU (Acoustic), HARM MAJ (Harmonic Major), HARM MIN (Harmonic Minor), WT (Whole Tone), OCT (Octatonic) and HEX (Hexatonic). Once an entire scale is selected, this page will also show you possible Harmonic Evolution (or maximally smooth Pressing scale 'voice-leadings') and Harmonic Contrast (maximally contrasted pc content change).

v1.0 ©2002 Michael Norris

This is a little Javascript program to convert an equal-tempered note name and octave into a frequency.

v1.0

This is a little Javascript program to convert a list of frequencies into a tab-delimited list of pitch classes (note name), with octave and cents deviation from 12TET, ready for copying and pasting into an Excel spreadsheet.

v1.0

This is a little Javascript program to calculate the results of a simple Frequency Modulation (FM) or Ring Modulation (RM) calculation into a tab-delimited list of pitch classes (note name), with octave and cents deviation from 12TET, ready for copying and pasting into an Excel spreadsheet.

v1.2 ©2015 Michael Norris

This is a little Javascript program that calculates the frequencies of partials in a harmonic series, and returns the results in a tab-delimited list ready for pasting into Excel.

v1.0 ©2002 Michael Norris

This is a little Javascript program that calculates the frequencies of partials in a harmonic series. You can also specify a stretch on the harmonics. For a version of this algorithm that outputs a tab-delimited text file for pasting into Excel, see here.

v1.0 ©2002 Michael Norris

This is a little Javascript program to produce a list of spectral peaks and their microtonal tunings, given a spectral analysis data file exported from Audacity, or a BPF file exported from Audiosculpt .

v1.0b12 ©2006 Michael Norris

This is a little Javascript program that lets you choose a pitch-class set, and then returns a bunch of information about it, primarily drawn from Jenny McLeod's and Peter Schat's Tone Clock theory. Information returned includes the Intervallic Prime Form (IPF), the Forte Name, and the "dissonance". Much reference is made to Tone Clock theory, drawn from the IPF tables in Jenny McLeod’s “Chromatic Maps”* (based on Peter Schat’s work). At the bottom of this page is a glossary explaining (some) of the terminology. One day I'll get round to explaining everything... :-)

v1.0 ©2002 Michael Norris. Based on the MODE db

This is a little Javascript program that contains about 800 different melodic modes (equal-tempered only), categorized into different types.

v1.0 ©2014 Michael Norris

This Javascript allows you to calculate the similarity functions between a list of different set-classes. It uses a number of similarity functions that have been published in peer-reviewed journals. Most of the them have been covered in the 1990 article on pc-set similarity by Isaacson.

v1.0b2 ©2006 Michael Norris

This script uses a set of user-defined "rules" to substitute text from one generation to the next, in a manner that mimics natural growth and decay processes.

v1.0 ©2008 Michael Norris

This is a little Javascript program that determines every possible pitch tessellation for any-sized IPF within any-sized equal-tempered subdivision of the octave