People writing about singers sometimes say that they act with their voices. This was often said about Leontyne Price. Maria Callas was said to "act" with both her voice and her body. What can this possibly mean? I suggest that it means the same thing as I mean when I talk about phrasing.
All singing has pitch, rhythm, tone and phrasing. Phrasing is.... Any music has an expected way in which it is phrased. I've discussed this it must be hundreds of times by now, and I begin to become discouraged. If it helps to say they "act with their voices," then so be it.
In many ways music is the creation of anticipation, the movement from one note to another, the feeling that more is to come. All the elements can contribute to this effect, but phrasing is the strongest.
Unphrased music just sits there. In the modern world we substitute deafening repeated bass notes for phrasing. You know what I'm talking about. When the car drives past your house, all you can hear is the bass. In my case this is my only contact with this type of music.
Stefan Zucker who writes for the Bel Canto Society has sent me a long article on What Sets Callas apart, and nowhere in it does he mention that her phrasing was exquisite. Why else would we sit through the ugly sounds she so often makes? Because we are masochistic? Or more likely because we recognize perfection when we hear it.