Jonathan Frakes asking Jordon Nardino to say "the Scottish play" instead of "Mackbeth" is caused by a superstition which is popular among actors who believe that saying "Mackbeth" brings bad luck.
Matt Mira's remark about how Anthony Rapp should record an album called "Ol' White Eyes" is a reference to Brent Spiner's album "Ol' Yellow Eyes Is Back".