Coltrane

A musical abacus written in ruby.

More info, story and purpose of the library here.

Chat room for discussing the project, answering questions, etc: https://gitter.im/coltrane-music/Lobby

CLI (Command Line Interface)

Installation

Compiled binary

There's an experimental compiled version you can download here. It has been tested only macOS High Sierra so far, but it should work on Linux and Windows as well.

macOS & Linux: You probably will need chmod +x coltrane before running it. Windows users: Please add the .exe extension to it before running it (via command prompt).

Ruby command

$ gem install coltrane

Once you install the gem the CLI is instaled in your system and it's ready to be used.

Usage

It allows you to query for notes and chords and display them on your favorite instrument. No sheet music reading skills needed. It also allows you to find scales with a chord and find chords shared between two scales (that is actually the main goal when I did this project).

Some screenshot examples:

As a library

Add this line to your application's Gemfile:

gem 'coltrane'

And then execute:

$ bundle

The whole library will be available under the Coltrane module. The CLI code won't be imported to your application as default. Here's a quick example on how to use it:

require 'coltrane'

puts Coltrane::Scale.major('C').sevenths.map(&:name)
# => ["CM7", "Dm7", "Em7", "FM7", "G7", "Am7", "Bm7b5"]

puts Coltrane::Scale.having_chord('Cmaj7').scales.map(&:name)
# => ["C Major", "G Major", "E Natural Minor", "A Natural Minor", "E Harmonic Minor", "B Flamenco"]

Roadmap

There's a lot of things that need to be done on this library, specially on the CLI:

• Separate into 2 gems: coltrane and coltrane-cli
• Make all output more colorful
• Refactor the CLI into a more succinct and elegantly organized architecture
• Amplify the test coverage
• Move Scale#chords method to NoteSet
• Write tests for the caching
• Write up a caching cleaning command
• Include CLI commands to output chord progressions
• Include a command to output a pretty HTML document containing the query

Contributing

Install the test suite (RSpec) by running good old bundle command

Fork the code, make your changes and maybe write a test or two. Then run:

Then run:

bundle exec rspec spec

Make sure the specs pass and submit a PR.

License

The gem is available as open source under the terms of the MIT License.