When teen queen Cyrus first played a pop star on “Hannah Montana,” her odds at actually becoming one seemed dubious at best. Certainly, achieving something like her dad’s “Achy Breaky Heart” moment appeared to be a stretch. But at 27, Cyrus has already outdone her country-crooner papa as an artist who has both commercial appeal and edgy artistry — from “Party in the U.S.A.” to current single “Midnight Sky.”