IANAL, but I suggest taking a look at this book: Making It in the Music Business: The Business and Legal Guide for Songwriters and Performers. http://books.go

IANAL, but I suggest taking a look at this book: Making It in the Music Business: The Business and Legal Guide for Songwriters and Performers. http://books.google.com/books?id=r8rU60NzsDMC&pg=PA42&lpg=PA42&dq=altering+songs+to+make+them+legal&source=bl&ots=M2cec0DpKm&sig=Q2A-BDOMvTHhWQ5dLevF2wkhPjA&hl=en&ei=PRxHTeyTG8P6lwfCs6wm&sa=X&oi=book_result&ct=result&resnum=10&ved=0CEsQ6AEwCTgK#v=onepage&q&f=false http://books.google.com/books?id=r8rU60NzsDMC&pg=PA42&#3... I think in the end you will be sued if you use any non public domain music. You may be found innocent in court under fair use, parody, education or some other loophole but it won't be until after buying your lawyer a new boat.