Welcome to Musical Composition with Opus+ !
Opus+ is free computer software which offers composers a new way of creating serious musical compositions. Opus+ is a java program that uses an algorithm called Constrained Random Generation (CRG) to create musical passages, and the content of the compositions produced can be controlled by the programmer setting constraints on the action of the software. There are three basic ways of using Opus+
The first is to generate complete compositions and use them exactly 'as is'. This use falls under the category of 'Found Music'.
The second is to generate music and then either edit the generated composition by hand, or incorporate parts of the generated composition into other musical contexts. This uses Opus+ to 'confound compositional habits' by creating novel musical material from which to work.
The third, and most flexible, is as a object-oriented java library which gives open access to the underlying object model used by Opus+. This allows java programmers to augment the normal operation of Opus+ by writing their own source code to control exactly how Opus+ generates its output. This means that students and researchers can use Opus+ to quickly implement literally any conceivable musical generation algorithm.
The outputs of the Opus+ program are a PDF file containing the musical score and a MIDI file containing a synthesized performance thereof, so the composition can be checked audibly.
In all three cases these outputs should be treated as 'sketches' of the new composition; the PDF file is not typeset to the standard expected by performers and musicians but is certainly good enough as a rough outline of the composition. The MIDI file produced has few dynamics, and when played directly the sound is at the mercy of the defaults used by the computer sound card. However, it is very easy to import the MIDI file into a 3rd party digital audio workstation such as Apple Logic Pro where it can be engineered, orchestrated, rearranged and produced to taste.
A fully functioning version of Opus+ is provided completely free of charge to individual users under the GNU Public License GPL3. We are however very interested to hear of new projects that use Opus+ and all we ask is that wherever it is used, the fact that it has been used is clearly stated on public media or announcements. See our license page for a full description of the license agreement and conditions of use.
Opus+ v1.0 is complete and ready for download from our downloads page. There are also examples of the music it creates on the examples page. These are the result of software test sequences used during development and they exhibit varying degrees of musicality. Further examples will be added as time goes on.
Contact us if you have any comments or suggestions about Opus+, or if you would like to share your Opus+ based compositions with others. We hope you enjoy using Opus+ !! :-)