markenbusiness reports on a case of itunes being able to identify a purported music plagiarism. Since iTunes uses a signature of the music to identify the performer, a download of one piece suggested it was done by someone else. And since from both the music is digitally identical in the wave forms, something fishy is up.
Of course, it could just be a database error, with the same musical signature stored for both performers. But since one pianist is involved in numerous such pieces, an investigation is being conducted.