Both J. Harrison Ghee and Christian Borle had small microphones taped to one ankle at Some Like It Hot this evening. A wire ran up their leg to (I'm guessing) the waist microphone pack.
Didn't see ankle mics on any of the other performers.
Ghee and Borle do quite a bit of individual and dual tapping. So it makes sense if one or two people are tapping, versus the entire company, to provide amplification for a large house like the Shubert.
Does anyone know how long this technology has been available and how widely it's used?