The central pairing of Rachel and Frank in this production does not exactly generate sparks, but succeeds well enough. As Rachel, Ashley Johnson-Moore embodies what you expect from a musical diva. Her appearance and her acting are fine, but her singing warrants a more measured response. Although she proves with “I Will Always Love You” and several other numbers that she can belt out a power ballad in a way that does Whitney Houston justice, Johnson-Moore has a tendency here to indulge in so much vocal ornamentation and so many dramatic pauses that many songs seem mannered. The all-important musical flow is impeded.