"After all, if you were casting the Scottish play, you'd want a male Macbeth and a female Lady Macbeth, both plum parts of equal status, so what's wrong with calling one an actor and the other an actress?" McGrath

Ah ha, Kevin. "you'd want a male McBeth and a female Lady McBeth. A leetle redundancy there? (Which makes me very happy- speaking as a literalistic queen of redundsncy.)

Why should one need to specify that a actor and an actress were needed for that particular play?