Blues singer SYL JOHNSON is suing stars including Michael Jackson, Will Smith and Tupac Shakur for copyright infringement, claiming they illegally sampled his song DIFFERENT STROKES without giving him credit for the track. The veteran star filed suit recently in an Illinois court, claiming Jackson's hit Blood on the Dance Floor, Smith's Who Stole the D.J. and the late Shakur's Peep Game all used his song - without paying for the rights to do so. Johnson - real name Sylvester Thompson has also filed papers against the legendary rap group N.W.A. for their song Real N**gaz Don't Die, and KRS-One, for his track Criminal Minded. The respective acts' record labels have also been named in the legal papers. Johnson is seeking unspecified damages, reports TMZ.com.