If you use aspects of a song but change it (for example changing lyrics to something your own to a song by someone else) that is illegal unless it passes the "parody" bar which is legal. If you are not doing a parody of the original, then you must have permission from the copyright owner to do so. When it comes to Nirvana, good luck. (Or really anyone else for good reason). You can COVER any song if you pay the appropriate fees to do so. But you need to keep the essence of the song to the original intent with simply a different arrangement of the original. Keep in mind, the arrangements of a song may be owned by someone different than the owner of the song itself.

When in doubt, get one of the widely available books on songwriting and copyright for a much more thorough explanation.

Brian Austin Whitney
Founder
Just Plain Folks
jpfolkspro@gmail.com
Skype: Brian Austin Whitney
Facebook: www.facebook.com/justplainfolks

"Don't sit around and wait for success to come to you... it doesn't know the way." -Brian Austin Whitney

"It's easier to be the bigger man when you actually are..." -Brian Austin Whitney

"Sometimes all you have to do to inspire humans to greatness is to give them a reason and opportunity to do something great." -Brian Austin Whitney