Desdemona was nodding her head before she was taking the phone to call Musa - just typing in her number right away at that point in time. Honestly she hoped that she answered - not knowing that Musa had Chris' number at all. While she was waiting for her to answer, Musa had been doing some of the rehearsal but was going off when she felt her phone vibrate - she wasn't needed at that point in time. She was stepping into a empty room away from everybody and was answering when she saw that it was Chris, just asking if he had heard anything. Although she was startled and relieved to hear Desdemona on the other end.