Theory

Theory

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.


This Javascript app converts 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. It also draws them with music notation, and allows you to export to a MusicXML file.


This Javascript calculates frequencies and 24TET pitches for Frequency Modulation or Ring Modulation algorithms. It prints the resultant frequencies in staff notation, and also will export to a MusicXML file for import into Sibelius.


This is a little Javascript program that converts a SPEAR 'Partials' file into a set of 24TET pitches.WORK IN PROGRESS!


This Javascript app accepts a spectral analysis data file exported from Audacity (or a BPF file exported from Audiosculpt), and analyses the likely spectral peaks and their microtonal tunings.


This web application uses concepts from Jenny McLeod’s and Peter Schat’s Tone Clock Theory to provide information about a selected pitch-class set (or 'Intervallic Prime Form'). Information returned includes the label, the Forte Name, tone-clock steering, and the ‘dissonance’ value. 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.


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.


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


This page shows the resultant pitches from all natural harmonics (up to the fourth harmonic) for orchestral strings. Note that for the third and fourth harmonic, there are two options for where to touch the string — the higher position, which is indicated using a harmonic circle, and the lower position, indicated using a touch-notation (diamond notehead).


This Javascript app 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.


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).


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


A series of presentations on tone-clock theory, algorithmic composition (Lindenmayer systems), New Zealand music and spectralism.