Random Melody Generator

Generate random melody under specific rules.

Getting started

Prerequisites

This project is written in Python 3.6. I haven't tested in other versions.

MIDIUtil library is used in my project. You can install it simply by using pip:

pip install MIDIUtil

How to use?

Simply run main.py. A standard MIDI file will be generated in output folder. The filename is midi_{timestamp}.mid.

You can play it using a media player (e.g. Windows Media Player) or import it into a Digital Audio Workstation (DAW).

Customize

By default, the melody is in major pentatonic scale, chord progression is C-Am-F-G (1-6-4-5), and percussion pattern is fixed. Also, the interval of notes within a phrase is constrained.

The rules can be modified in rules.json.

You can also adjust the length of song and tempo in song_settings.json.

rules.json

Parameter	Description
notes	Defines the notes used for composition.
interval_upper	Defines the upper bound of interval of notes. The values in this list will be randomly chosen.
interval_lower	Defines the lower bound of interval of notes. The values in this list will be randomly chosen.
rhythm	Defines rhythm pattern for melody. The numbers are in beats (quarter notes).
seq_chord	Defines the chord sequence. Notes in each sub-array will be played simultaneously to form a chord.
seq_perc	Defines the percussion sequence. The first element in the sub-array denotes the drum sound, and the second element denotes time value in beats.
velocity	Defines the velocity of strong, intermediate and weak beats.

song_settings.json

Parameter	Description
length	Defines the length of song.
tempo	Defines the tempo of song, measured in Beats per Minute (BPM).

Credits

• The whole project is written in Python (python.org).
• The project uses MIDIUtil library by MarkCWirt.
• I would appreciate ScoreDraft by fynv. My project is partially inspired by ScoreDraft. Since ScoreDraft uses scripts to compose music, I found its potential to automatically generate music. My algorithm of randomly generating melody was initially tested on ScoreDraft.