Six Degrees vs Octavarium

    Well... um... I know nobody's gonna listen to me, but the overall concept behind Octavarium must be taken into consideration when you begin to talk about musical "plagiarism." The concept of course dealt with the cyclicity of the universe, how everything that goes up must come down, etc... And of course the universe of Dream Theater deals largely with its influence and with bands that have excited them over the years. So "Never Enough" is done in the style of a Muse song, but with the delivery and touch of coming from Dream Theater. This is completely by design—Muse's sound is in effect coming "full circle" through DT.
    In fact, this isn't that far from what all of music really is. Without influence from another artist, music doesn't evolve—there would just be an absence of ideas. A band digs another band's sound and makes it their own. And if Dream Theater isn't copying Muse or whoever note-for-note, there's nothing illegal taking place. So there's no plagiarism.

(Besides, why would Portnoy and co. be stupid enough to perform a Muse song and call it their own??)

    If there's still any doubt to the validity of DT's work on Octavarium as their own, then look at Steve Morse's "Major Impacts" and "Major Impacts 2." With these albums, he pays homage to his favorite influences (John McLaughlin, Alex Lifeson, Kansas, Cream, etc.) through original compositions played in the style of his influences. But I wouldn't dare call any of them "plagiarism", as the fact that Morse gives his signature playing and songwriting abilities gives a unique twist to a familiar style. Same with DT and Octavarium.