A microtonal autotuner plugin.

Uses the Signalsmith Stretch library to do the pitch shifting and MTS-ESP to pull the tuning.

Built plugins are available for Mac, Windows, and Linux on the github releases page.

This plugin maps each frequency in the input onto the nearest frequency in the MTS-ESP tuning.

For example, I recorded myself whistling a continuously increasing pitch, then retuned the recording into 5EDO (five equal divisions of the octave). Here are the spectrograms of the unprocessed audio (left) and the output of the plugin (right):

The continuous increase in pitch in the original audio is converted into a quantized 'staircase' on the pitches of 5EDO.

Here's the spectrogram of the processed audio with the 5EDO frequencies added as black lines:

Note that all frequencies, the fundamental and higher partials alike, are mapped onto the 5EDO frequencies. This allows the autotuning to work on polyphonic input. It also means the timbre of the output will in general be inharmonic, since the higher partials may not be at multiples of the fundamental frequency.

• Add the Xentotune plugin to the track to be retuned.
• Use an MTS-ESP source like MTS-ESP Mini, Surge XT, or Wilsonic to set the tuning.

To build from source:

    $ git clone --recurse-submodules https://github.com/narenratan/xentotune
    $ cd xentotune
    $ cmake -B build -DCMAKE_BUILD_TYPE=Release
    $ cmake --build build --config Release