Music, both lyrics and melody, are protected by copyrights. Unless you get permission from the owner of the copyrights you could expose yourself to quite significant liability under the statutory damages portion of our copyright laws. The only defense would be if the lyrics themselves could be considered part of the public domain and your use on a t-shirt fair use. But it does not sound from the brief information available that this would be the case.
Answered on Feb 06th, 2013 at 4:55 AM