I lived on the Upper West Side during the park run, and in addition to seeing it in the Delacorte, would walk over at night and listen to the show. Ronstadt was superb every time. When the show moved to B'way, I thought they allowed her to sing a bit more of the score in her belt, but I could be wrong (and will be corrected I'm sure). In any case, she was stunning on B'way, her "Poor Wandering One" and act one close superb. I never heard anyone find her vocals lacking -- fully accepting the amplification -- even if she was never considered anything close to an actor. She had maybe two lines that weren't sung, and their flat amateurishness ended up adding to the charm of the whole piece. Ronstadt's use of her voice was expert, and when she was singing, any awkwardness vanished.