At Eastman -- and I interviewed for theory by the way -- there was a battery of 3 interviews: one for keyboard/aural skills (no dictation), one for research, and one sight analysis session. Keep in mind: you may not actually get interviews with people who read your submissions! I wasn't, and I was interviewed by a single faculty member who wanted to get a general idea of my research area. The musicology applicants, on the other hand, were interviewed by a panel of three people who read the apps. Accordingly, they were asked targeted questions about the work they submitted. In other words, be ready for a variety of conditions in your interviews, folks.
All in all, Eastman theory interviews seemed most interested in identifying fit, to be sure, but also in identifying who would be a good TA, I'm not convinced being a top-notch scholar was the top concern.