A voice-leading algorithm that accepts RomanText inputs and produces harmonized scores.

Developed by Néstor Nápoles López. A fork of Eric Zhang's harmony.

Powered by music21.

Why is it called romanyh?

1. Emphasizes the importance of roman numeral inputs.
2. Anagram of harmony.

Usage

Example input in RomanText form:

example.rntxt

Composer: Néstor Nápoles López
Title: A unit test in C

Time signature: 3/4 

m1 b1 C: I b2 ii b3 iii
m2 b1 IV b2 Cad64 b3 V
m3 vi b2 V6 b3 viio65/i
m4 b1 I6 b3 V
m5 b1 c: i b2 iio b3 III
m6 b1 N6 b2 Cad64 b3 V
m7 b1 It6 b3 V
m8 b1 Fr43 b3 V
m9 b1 Ger65
m10 b1 iv
m11 b1 V b3 V
m12 b1 I

As a stand-alone binary

Generate a 4-part harmonization:

$ python -m romanyh example.rntxt

This generates a MusicXML file called example.xml within the current directory.

If you have set up music21 to work with your music notation editor, you can add the --show flag:

$ python -m romanyh example.rntxt --show

This will render the harmonized score in your music notation editor (hopefully).

As a library

romanyh exposes two functions: harmonize and harmonizations. Both receive a path to a RomanText file.

import romanyh

inputFile = "example.rntxt"
score = romanyh.harmonize(inputFile)
score.show()

The function returns a music21.stream.Stream object.

The difference between harmonize and harmonizations is that the latter is a generator. It produces a different harmonization in every iteration:

import romanyh

inputFile = "example.rntxt"
for score in romanyh.harmonizations(inputFile):
    score.show()

This is useful when you want to generate alternative voicings for the same input.

The harmonizations are sorted according to the voice-leading algorithm. You can expect each successive harmonization to be worse than the previous one.

Similarly, you can expect the first harmonization to always be the best one. At least according to what the rules of the algorithm decide.

The first harmonization provided by harmonizations is always the same than the one provided by harmonize.

License

Licensed under the BSD 3-Clause License.