diamond

Features

Classic arpeggiator functions
Uses unimidi for cross-platform compatibility
Run as a background thread for live coding
Sync to and from MIDI clock
Sync between multiple Diamond instances
Preset and user-definable pattern algorithms

Installation

gem install diamond

Requirements

Ruby 1.9.2 or JRuby in 1.9 mode

Gem Dependencies:

midi-eye, midi-message, topaz, and unimidi

these will install automatically with the gem

Usage

require "diamond"

First, select a MIDI output using unimidi. (more about this…)

@output = UniMIDI::Output.first.open

The Arpeggiator has a number of optional parameters. For this example, here's a straightforward setup

opts = { 
  :gate => 90, 
  :interval => 7,
  :midi => @output,
  :pattern => Diamond::Pattern["UpDown"],
  :range => 4,     
  :rate => 8
}

Create an Arpeggiator object, passing in a tempo value and the options above. In this case the tempo will be 138 BPM

arp = Diamond::Arpeggiator.new(138, opts)

Of course, an arpeggiator needs notes to work with. As you might expect, it's easy to use a MIDI input for that. (see example). However, again for the sake of simplicity here's a chord in Ruby

chord = ["C3", "G3", "Bb3", "A4"]

Use Arpeggiator#add and Arpeggiator#remove to change the notes that the arpeggiator sees.

arp << chord # same as add
arp.add("C5")
# etc

Now start the arpeggiator. By default, the arpeggiator will run in a background thread so if you are working in irb this will allow you to live code, sync it other arpeggiators, or just run another foreground process. (To start in the foreground, just pass :focus => true to Arpeggiator#start)

arp.start

All of the arpeggiator options can be controlled on the on the fly

arp.rate = 16
arp.gate = 20  
arp.remove(["C5", "A4"])

This screencast video shows Diamond being live coded in this way. (Read how this is done)

Check out these posts and examples for more…

Posts:

Live coding Diamond and syncing multiple arpeggiators to each other

Examples:

(more…)

Author

Ari Russo <ari.russo at gmail.com>

License

Apache 2.0, See the file LICENSE