Awesome

MicroMIDI

A Ruby DSL for MIDI

micromidi

Features

Cross-platform compatible using MRI or JRuby.
Simplified MIDI and Sysex message output
MIDI Thru, processing and custom input events
Optional shorthand for live coding

Installation

gem install micromidi

or using Bundler, add this to your Gemfile

gem "micromidi"

If you're using Linux, the libasound and libasound-dev packages may be required

Usage

Here's a quick example that plays some arpeggios

require "midi"

# prompt the user to select an input and output

@input = UniMIDI::Input.gets
@output = UniMIDI::Output.gets

MIDI.using(@output) do

  5.times do |oct|
    octave oct
    %w{C E G B}.each { |n| play n, 0.5 }
  end

end

This next example filters outs notes if their octave is between 1 and 3. All other messages are sent thru.

Output is also printed to the console by passing $stdout as though it's a MIDI device

MIDI.using(@input, @output, $stdout) do

  thru_except :note { |msg| only(msg, :octave, (1..3)) }

  join

end

This is the same example redone using shorthand aliases

M(@input, @output) do

  te :n { |m| only(m, :oct, (1..3)) }

  j

end

Finally, here is an example that maps some MIDI Control Change messages to SysEx

MIDI.using(@input, @output) do

  *@the_map =
    [0x40, 0x7F, 0x00],
    [0x41, 0x7F, 0x00],
    [0x42, 0x7F, 0x00]

  node :roland, :model_id => 0x42, :device_id => 0x10

  receive :cc do |message|

    command @the_map[message.index - 1], message.value

  end

end

Here are a few posts explaining each of the concepts used here in greater detail:

Documentation

rdoc

Author

Ari Russo <ari.russo at gmail.com>

License

Apache 2.0, See the file LICENSE