MicroMIDI

A Ruby DSL for MIDI

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:

• Output
• MIDI Thru and Processing
• Binding Custom Input Events
• Shorthand
• Sysex
• Etc

Documentation

• rdoc

Author

• Ari Russo <ari.russo at gmail.com>

License

Apache 2.0, See the file LICENSE

Copyright (c) 2011-2015 Ari Russo