LilyPond Ruby is a Ruby library for controlling LilyPond, a music notation software. It allows LilyPond files, compile them into various formats (such as PDF or MIDI), and access LilyPond's various functions and features through Ruby code.

Download and install LilyPond from http://lilypond.org/download.html

To install LilyPond Ruby, run the following command:

gem install LilyPond-Ruby

Or add this line to your application's Gemfile:

gem "LilyPond-Ruby"

And then execute:

bundle install

I built this gem with Rails in mind, so in my app's config/initializers directory I added the lilypond.rbfile with the following information:

require "lilypond-ruby"

LilyPond.configuration do |config|
  config.default_output = :pdf # options: [:pdf, :svg, :png]
  config.destination_directory = Rails.root.join("storage", "lilypond") # Where the output files will go.
  config.lilypond_path = Rails.root.join("public", "lilypond-2.24.1", "bin", "lilypond") # wherever your LilyPond installation command lives.
end

Here's an example of how to use LilyPond Ruby to generate a PDF file from a LilyPond file:

require 'lilypond-ruby'

lilypond_code = File.read('score.ly')
file_name = 'score.ly'

LilyPond.generate_with_lilypond(file_name, lilypond_code, :pdf)

Bug reports and pull requests are welcome on GitHub at https://github.com/Okomikeruko/LilyPond-Ruby. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

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