This Play is referred to by The Shower Principle part of 30 Rock Season 6
TGS plans a parody skit of the Shakespeare play 'Macbeth'. Jenna doesn't want to be part of the skit, because she believes that there is a curse involved.
The Tragedy of Macbeth (commonly called Macbeth) is a tragedy by William Shakespeare about a man who commits regicide so as to become king and then commits further murders to maintain his power.