jchord - toolkit for working with chord progressions

What's this then?

jchord is a Python package which provides tools for working with chord progressions. jchord:

• has object representations for notes, chords, and progressions (in the Western 12-tone system)
• knows about naming conventions for chords, and can convert back and forth between objects and names
• can be used as a converter between strings, text files, XLSX files, PDFs and MIDI files (see "converter script" below)

Get it

Basic installation:

pip install jchord

Installation with dependencies for reading and writing MIDI/XLSX/PDF files:

pip install jchord[midi,xlsx,pdf]

Convert between formats

If you just want the converter functionality, invoke jchord on the command line:

usage: jchord [-h] [--midi MIDI] [--pdf PDF] file_in file_out

Converts between different representations of the same format

positional arguments:
  file_in      Input progression as string, .txt, .xlsx or .midi
  file_out     Output file as .txt, .xlsx, .midi or .pdf

optional arguments:
  -h, --help   show this help message and exit
  --midi MIDI  comma separated list of arguments for midi, e.g. tempo=8,beats_per_chord=2
  --pdf PDF    comma separated list of arguments for pdf, e.g. chords_per_row=8,fontsize=30

Example:

jchord "Cm A E7 F#m7" example.mid --midi tempo=80,beats_per_chord=1

As a library

Here is an example that parses a chord progression written as a string, transposes it upwards by 2 semitones, converts it back to a string and then creates a midi file from it.:

from jchord import ChordProgression, MidiConversionSettings
prog = ChordProgression.from_string("C -- Fm7 -- C -- G7 -- C -- E7 Am F Bm7b5 E7 Am9 F Bo C69 --")
prog = prog.transpose(+2)
print(prog.to_string())
prog.to_midi(MidiConversionSettings(filename="example.midi", tempo=100, beats_per_chord=2, instrument=4))

Output:

D       --      Gm7     --
D       --      A7      --
D       --      F#7     Bm
G       C#m7b5  F#7     Bm9
G       C#o     D69     --

For more examples, see the documentation.

Documentation

Documentation lives here: jonathangjertsen.github.io/jchord/

Contributing

To contribute, open an issue or create a Pull Request in the Github repo.