Ourouborous

by Matthew Lyon matt@flowerpowered.com

Description

Ourouborous is a re-thinking of a MIDI sequencer system I built in Max/MSP several years ago and never got around to finishing.

Features

Ourouborous is made up of several components:

• The Scheduler:
  This is currently a remote timer using Kernel#sleep. In the future it will also be able to subscribe to a network scheduler to synchronize multiple processes/computers to the same timer. It uses a time-independent "tick" system which works out to 480 pulses per quarter note at a given tempo, so you can specify durations in musical terms, not fractional seconds.

• Scheduler Subscribers:
  Mixin Ourouborous::Schedulable and your class will have its own event queue (Ourouborous::Schedule) that can be driven by a scheduler when added to that scheduler's subscriptions.

• Abstract MIDI Interfaces: Things that generate MIDI shouldn't have to know or care about the details of actually getting it where you want it to go. In /lib/ourouborous/interfaces/midiator.rb there is an example interface for talking to Ben Bleything's MIDIator library. Soon there will be another interface for sending MIDI over UDP via Open Sound Control.

• MIDI Generation: Mixin Ourouborous::MIDI::Generator into any schedulable class there are some helpers for scheduling notes and sending them to an abstract MIDI interface.

• Sequencers: A base library of classes to plug into the scheduler that sequence midi. Currently:

  • A Metronome! For all your piano practice fun. Handles arbitrary time signatures. See /examples/metronome.rb
  • A Probablistic Step Sequencer. Inspired by Archaeopteryx. See /examples/beats.rb

• Effects: None yet. Modify your midi in real-time.

• Devices: Specific Handlers for dealing with outside devices or actors. These could include input specifically from MIDI keyboards and knob boxes, a Monome or Lemur device that handles input and displays output, handling output to specific synthesizers you want to interact with in a particular way, etc.

  Currently:

  • Monome. Subdivide your grids, handle button presses, turn the lights on or off, and if you add it to a scheduler, blink the lights on or off easily. See /examples/monome_beats.rb for how to integrate this with the step sequencer.

Requirements

• The example provided requires Ben Bleything's Midiator gem install bleything-midiator
• The Monome device requires my own Datagrammer gem install mattly-datagrammer

License

Copyright (c) 2008 Matt Lyon

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.