Music Jokes for the Holidays

My parents gave me a T-shirt that says, "E = Fb, The Einstein Theory for Musicians" which is pretty damn funny. But being the theory geek that I am, I had to think of a way to more closely mimic the theory of relativity in music terms. And I came up with one, with the added bonus that it involves an operation that only graduate music theory students ever hear about:

E = M4(C#)

M is an operation in pitch class theory, usually only associated with 12-tone rows and only as M5 or M7. The operation is a multiplier, multiplying the pitch class(es) that follow it in parentheses by the subscripted number. M5 and M7 are particularly cool because they convert the chromatic scale to the circle of fifths and vice versa. M4 wouldn't be very useful as a 12-tone operator, as the results on a typical row would end up with only three pitch classes, (0 4 8). But it will convert a C# (pitch class 1) to an E (pitch class 4). In other words: 4 = 4 x 1. And people say that music theory is hard.