I would like to know the proper way to say "sing in or with" a beautiful voice. I mean also birds not only humans. so, is it "he sang in a beautiful voice" or "he sang with a beautiful voice".
I would be inclined to say, "......sing with a beautiful voice" and "......sing in a beautiful tone/way/pitch". But birds aren't usually describedas having a voice. So, you might say that a bird sings with a beautiful sound.