HarmoniX¹

HarmoniX is an automatic harmonizer for monophonic melodies. Simply provide it with a .wav file of a tune, and it will spit out a new .wav file of the audi in perfect four-part harmony.

How it works

HarmoniX consists of three main components:

1. Pitch detection using the YIN algorithm².
2. Melody-to-chord generation using a bidirectional LSTM³.
3. Pitch shifting using a digital phase vocoder⁴.

See HarmoniX.ipynb for the code and more details.

Running the code locally

First, install the dependencies using the following commands:

python3.11 -m venv env
source env/bin/activate
pip install -r requirements.txt

Then go to HarmoniX.ipynb and run all the cells. By default, the code does not save the trained PyTorch model. However, you can uncomment the commented-out code block to save your own model if you decide to change any hyperparameters.

Examples

See examples.ipynb

Footnotes

1. Pronounced "harmonic". The "X" is an uppercase Greek chi. ↩

2. http://recherche.ircam.fr/equipes/pcm/cheveign/ps/2002_JASA_YIN_proof.pdf ↩

3. https://archives.ismir.net/ismir2017/paper/000134.pdf ↩

4. https://www.di.ens.fr/~mallat/papiers/Vocoder.pdf ↩