It deals with all sorts of calculations around music theory and allows for graphical representations of it

Ruby MIDI DJing/live-coding thing

Jazz Model - A data model for Jazz theory and other cool stuff.

Platform independent realtime MIDI input and output for Ruby

midilib is a pure Ruby MIDI library useful for reading and writing standard MIDI files and manipulating MIDI event data.

A nice Ruby interface to your system's MIDI services. MIDIator was inspired by Topher Cyll's fantastic Practical Ruby Projects book. In it, Topher describes how to interact with the MIDI providers in OSX, Linux, and Windows. As I was reading the book, I noticed some things I would do differently, which got me thinking that maybe it would be valuable to package up my modifications to the book's code and release it as a gem.

A Ruby DSL for MIDI

Ruby Music and Midi App there are currently two different apps one for playing live and the other for writing to a midi file..Currently working on creating the chord System and is requesting ideas that you the user would like to see come out of a app like this..

COmpact Sequencing sYntax

A MIDI arpeggiator in Ruby

𝄝 Displays popular ukulele chords for the popular `GCEA` tuning

PatchMaster is a MIDI processing and patching system. It allows a musician to reconfigure a MIDI setup instantaneously and modify the MIDI data in real time.

A Ruby DSL for generating Lilypond guitar tablatures.

Ruby bindings for OS X's high-quality music sequencing API

A console music library explorer and player