Round II was over mash-ups.

DJ Danger Mouse "mashed" the Beatles' White Album with Jay-Z's the Black Album, producing "The Grey Album." EMI issued a cease-and-desist order, but while the DJ removed his work from the internet, other sites did not.

Mashups offer a compelling new twist on songs we've heard before - but they apparently signal more battles to come. Another band performing Beatles parodies - with Metallica-style chords -- was also threatened with lawsuits.

In an unexpected twist, rushing to defend their right to distribute music parodies online was: Metallica's Lars Ulrich.