Diamond
MIDI arpeggiator in Ruby
Features
- Classic arpeggiator functionality and patterns
- OSC and MIDI remote control
- MIDI clock IO
- Multiplex clocks and arpeggiators
- Suited to live coding
- Generative arpeggio patterns
Installation
gem install diamond
or with Bundler, add this to your Gemfile
gem "diamond"
Usage
require "diamond"
First, select a MIDI output using unimidi. (more about that here)
@output = UniMIDI::Output.gets
The Diamond arpeggiator has a number of optional parameters. For this example, here's a straightforward setup
options = {
:gate => 90,
:interval => 7,
:midi => @output,
:pattern => "UpDown",
:range => 4,
:rate => 8
}
arpeggiator = Diamond::Arpeggiator.new(options)
Create a clock object, passing in a tempo value. In this case the tempo will be 138 BPM
clock = Diamond::Clock.new(138)
Point the clock to the arpeggiator
clock << arpeggiator
The arpeggiator will play based on inputted notes or chords; a MIDI input can be used for that. (see example). It's also possible to enter notes in Ruby:
chord = ["C3", "G3", "Bb3", "A4"]
Use Arpeggiator#add
and Arpeggiator#remove
to change the notes that the arpeggiator sees. (Arpeggiator#<<
is the same as add)
arpeggiator.add(chord)
arpeggiator << "C5"
Starting the clock will also start the arpeggiator:
clock.start
Note that by default, the clock will run in a background thread. If you're working in a PRY/IRB/etc this will allow you to continue to code while the arpeggiator runs. To start in the foreground, pass :focus => true
to Clock#start
.
All of the arpeggiator options can be controlled while the arpeggiator is running.
arpeggiator.rate = 16
arpeggiator.gate = 20
arpeggiator.remove("C5", "A4")
This screencast video shows Diamond being live coded in this way. (Note that the API has changed a bit since 2011 when the video was made).
This blog post explains what is happening in the video.
Posts
- Introduction
- Live coding Diamond and syncing multiple arpeggiators to each other
- A note about live coding in IRB with OSX
Examples
- Control via OSC
- Define a Pattern
- Feed notes to Diamond using a MIDI controller or other input
- Feed notes to Diamond using MIDI message objects
- Sync multiple Arpeggiator instances to each other
- Sync Diamond to external MIDI clock
- Use Diamond as a master MIDI clock
Other Documentation
Author
- Ari Russo <ari.russo at gmail.com>
License
Apache 2.0, See the file LICENSE
Copyright (c) 2011-2015 Ari Russo