From the play "Proof"
A male mathematician invites a woman to see his band perform. The band's all
math geeks, and he admits they're way down the list on the performance
He tells her they do a song called "i" - lower case. The don't play anything.
They just stand there for three minutes, because "i" is... an imaginary
He presumes this the reason they're near the bottom of the performance list.