This app calculates the frequencies of partials in a harmonic or subharmonic series, with the ability to stretch or compress the series. Results are generated as a tab-delimited list, ready for pasting into Excel or Google Sheets, or can be downloaded as a MusicXML file for importing into MuseScore, Dorico or Sibelius.
Frequencies are calculated using the following formula: $f_{n}=f_{0}(s(n-1)+1)^{x}+\alpha$, where $f_{0}$ is the fundamental frequency, $s$ is the Scaling (stretch) Factor, $n$ is the partial number, $x$ is the Exponent and $\alpha$ is the Frequency Addition constant. If the ‘Subharmonics’ checkbox is ticked, however, then frequencies are calculated as: $f_{n}=\frac{f_{0}}{(s(n-1)+1)^{x}}-\alpha$
How to use
- Either select a note name and octave, or enter a fundamental frequency directly into the ‘Fundamental Frequency’ box.
- Set any desired ‘harmonic stretching’ parameters, or leave as the default.
- Enter the number of partials you wish to generate (default is 16)
- Click ‘Calculate’ to generate tab-delimited output, music notation and spectrum.
- Once generated, click ‘Play Frequencies’ to hear the harmonic series as sine tones, or click ‘Download MusicXML’ to export out to a MusicXML file.
Music Notation
* Note that Sibelius does not correctly import quartertones from MusicXML.