zgomot is a simple DSL for writting MIDI music.

A music library and domain-specific language for generating music via MIDI.

An ffi wrapper around the cross platform midi library portmidi, part of the portmedia framework

Aubio is a tool designed for the extraction of annotations from audio signals. Its features include segmenting a sound file before each of its attacks, performing pitch detection, tapping the beat and producing midi streams from live audio.

Builds Audulus patches based on WAV or MIDI file inputs

Powering MIDI through ruby

Peas defines constants from music theory and allows one to perform math with them. Currently supports pitches (as MIDI values), pitch classes, and intervals using semitones, wholetones, chromatic, latin or diatonic abbreviations.

Filter Program Change (PC) or Control Change (CC) events from MIDI files.

== Midi experiments

represent rhythms as symbolic Strings and write them to MIDI

A Ruby library to send manufacturer-specific or instrument-specific MIDI messages

This gem provides programmatic access to the Novation Launchpad MK2. LEDs can be lighted and button presses can be evaluated using launchpad's MIDI input/output.

A gem that provides MIDI in to ruby via OSX CoreMIDI

This gem provides an interface to access Novation's LaunchPad programmatically. LEDs can be lighted and button presses can be evaluated using launchpad's MIDI input/output.

Quick and easy prototyping for Arduino-based MIDI pedalboards

Universally patch controller messages such as MIDI and OSC between devices

program/play (MIDI) music from your code.

Ruby/IFF is a Ruby library for loading and serializing file formats based (more or less loosely) on the IFF standard; these include many popular file formats like MIDI and WAV

SMF is a "Standard MIDI File" module for an object-oriented scripting language Ruby.

Stretto is a Ruby implementation of JFugue, an open source library originally written in Java by David Koelle for programming MIDI.