This article describes a scheme to have a computer generate every possible "8-note, 12-beat melody combo" and release it under a Creative Commons license so that anyone can use it (not exactly public domain, but close enough for practical purposes). The idea is that from now on it will not be possible to copyright a basic melodic theme because it will already have been written in a tangible form.
Will this really forestall copyright infringement suits?
Edit: to clarify. Suppose I write a melody, and someone else claims that they wrote the same melody and hence have copyright on it. Can I point to the existence of the melody in this generated corpus as a defence?