The pre-emptive
E included:
"/--e/ /----e-/ /---/ /--/ /---------/ /---/ /---e/ /----/ /--e/ /-----e-/."
"/-/ /----/ /-----/ /-e'-e/ /-e-----/ /----/ /----e-/ /----e--/ /-e-e/."
I doubt anyone will know what episode this is from without doing some sort of search - trust me, it's obscure. There is a reason I chose it though...
Guess away.