A sketch shows confessed al-Qaida conspirator Zacarias Moussaoui in court as defense attorney Edward MacMahon (center) and prosecution counsel David Novak (right) speak with U.S. District Judge Leonie Brinkema on March 13, 2006, in Alexandria, Va.
Canon-making is a core part of rap fandom, the subject of endless barbershop parleys and message-board battles. But something curdles when the companies that control the music business enter the chat.