"MC's Act Like They Don't Know" is a song from KRS-One's 1995 eponymous album. It contains production from DJ Premier that samples "Yesterdays" by Clifford Brown, and interpolates "The Breaks" by Kurtis Blow. Its lyrics deal with how many rappers who achieve positive chart positions and other commercial awards cannot perform well live.
Besides appearing on KRS-One and on the "MC's Act Like They Don't Know/Represent the Real Hip-Hop" single, it has appeared on many compilation albums. It appeared on compilations including 1996's Hip Hop's Most Wanted, 1997's Gangsta Hip Hop, Vol. 5, Hot Joints, Vol. 1, 1999's Best of D&D Studios, Vol. 1, 1999's Discover the Rhythm of Hip Hop, 1999's Ill Rated, 1999's Real Hip-Hop: Best of D & D, Vol. 1, 2000's A Retrospective, 2002's Hip Hop, Vol. 2, 2002's Rappers Delight and 2003's Best of Rapture's Delight