Rosita and Big Bird's Favorite Letter Song

This is a song by Big Bird and Rosita on Sesame Street. They try to sing about the letter "S" while an "S" is stuck on Rosita's nose.

Lyrics
Big Bird: What's our favorite letter?

Rosita: Would you care to guess?

Big Bird: It's when it starts out special.

Rosita: And ends in happiness.

Big Bird: It's wurvy and it's curvy.

Rosita: And it's on my nose.

Big Bird: Is it the letter S?

Rosita: The letter S.

Big Bird: Do you suppose?

Rosita: What's our favorite letter?

Here's another clue.

Big Bird: It's right there when you go to sleep.

Rosita: Or when you're in a stew.

Big Bird: It's sneaky and it's snakey.

Rosita: And it's stuck on kite.

Big Bird: If you said letter S, you guessed it right.

Rosita: If you said letter S...

Both: You guessed it right.