Hathaway has a beautiful singing voice, and earned raves when she did CARNIVAL at Encores! some time ago.
I think Biel's voice could use some training, but she definitely has some nice chops. Good for her.
Now, is Ellen Greene singing that badly as a character choice since Miss Adelaide has a cold? I dislike her in those clips, she's playing Audrey not Miss Adelaide. Biel and her do seem to have nice chemistry during "Marry the Man Today" though. Chemistry is what I think is lacking between Mitchell and Biel, frankly, I don't think Mitchell does a great job in those clips. I mean, he has a terrific voice, but the acting isn't there.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"