[cduan]

Ignorance of the law is never an excuse, but ignorance of the facts is frequently an excuse. "Innocent" copyright infringement can occur when you think it is legal to copy something (e.g. the copyright has expired, it is fair use, etc.), but it turns out that you are mistaken.

However, for copyright to apply, you actually have to copy something. If you coincidentally come up with the exact same song that someone else wrote already, but you never heard about the other person's song, you would not infringe copyright in the other person's song.

In contrast, patents infringement is "strict liability," meaning that you can infringe a patent without even knowing that the patent exists.

[goodness]

If this is really the case, then it seems to be a loophole for a reverse scenario. You write a computer algorithm to generate vast collections of music. Since the computer, pretty much by definition, is ignorant of other music then you can claim copyright over everything it generates. Wait for it to produce "copies" of popular melodies and then you can publish cheap clones or license popular songs to people for a fraction of the cost of the originals.

If there is an objection that the computer isn't considered a person, then form a corporation and copyright the songs to the corporation. The corporation is equally ignorant of any other music. Human judgment is only exercised by a second corporation that searches the first corporations extensive database to find popular melodies to license.

[gojomo]

Courts are not computers; they apply subtle judgments based on a total reading of scenario.

If your intent was to discover and then market tunes identical to popular copyrighted tunes, a court can view the totality of your system as 'copying' existing works. If your two corporations exist to obscure the real intent of the people behind them, a court can treat them as co-defendants.