Category Archives: 612-et

Homage to Ptolemy – a systematic generation of just intonation tetrachords

Ptolemy titlepageThe author generates a handsome collection of tetrachords by using an archaic arithmetical procedure. He embeds various historical tetrachords into the group, with special focus on Ptolemy. He provides historical context. He also presents a generalized classification of tetrachord types. Finally he demonstrates the usefulness of the schisma resolution in modelling the fine grain of n-limit Just Intonation.

Click on the links to see the articles in your browser or right-click to save the files to your drive.

http://siementerpstra.com/writings/Terpstra-Ptolemy.pdf

http://siementerpstra.com/writings/Terpstra-PtolemyDiagrams.pdf

 

The Laws of Harmonics

LawsofHarmonics titlepageStarting in the middle 1980’s, around the time that I wrote up A Short List of Musical-Cosmological Monochords, I began a patient compilation of diagrams. Most of them consisted of elaborate tables showing numerous just ratios calculated in cents, as well as some speculative monochords and representations of the Harmonic Series. I meant this work to accompany a text that sums up my investigations into Harmonics. Inevitably, it reflected my interests during the seventies and early eighties – just intonation, drone-based music, and monochords. I never got around to writing the text, though I left a couple of pages of notes. After a few years I scrapped the whole project and archived it under the rather imposing heading: The Laws of Harmonics. Recently I dragged it out of its storage to reconsider the project.

Click on the links to see the articles in your browser or right-click to save the files to your drive.

http://siementerpstra.com/writings/Terpstra-LawsofHarmonics.pdf

http://siementerpstra.com/writings/Terpstra-LawsofHarmonicsDiagrams.pdf