Dear Dick,
A honey of a pun, indeed, and I bow to the correction. Was in a hurry and let memory serve; should have looked it up. In pitiful and only partial defense, allow me to point out that it is the repetition of the lines "Can do, can do, if he says the horse can do; can do, can do!" in each of the three song parts' chorus, that lead cast members and others in the productions which I recall from ancient history, to reduce the unwieldy "Fugue" pun to the simpler "Can Do" when referring to the song in question. Sorry, just lazy today. Will try to improve accuracy in future.
Always,
Shula