Unbelievable! No one sings like that anymore. I think this Jerry-Kramer conversation from the episode "The Opera" sums it up pretty well:
KRAMER: So, what do you think?
JERRY: About what?
KRAMER: About the opera.
JERRY: Nah, I don’t wanna go.
KRAMER: You gotta go.
JERRY: I-I-I don’t like the opera. What are they singing for? Who sings? You got something to say, say it!
KRAMER: Jerry, you don’t understand, that’s the way they talk in Italy. They sing to one another. (Kramer starts to sing in bad Italian.)
JERRY: All right, all right.
KRAMER: That’s the way it was, you know. You listen to the language, its got that sing songy quality. It’s the language Jerry, the language.
JERRY: So why don’t they talk like that now?
KRAMER: Well its, uh, well its too hard to keep up, you know. They were tired.
We’re tired of your singing, Neal!