This is the classic goodnight song - cheerful and easy to sing along to. From the movie The Sound Of Music, which is also a movie classic, it was sung twice - the first time to say goodnight, the second time to say adieu.
Other songs like this one:
For Good from the musical Wicked
Duet between the characters Elphaba and Glinda in the musical play Wicked, inspired by the story of the Wizard of Oz. It is sung at the end of the play, and reflects on how their friendship has changed them "for good", before they part: "It well may be/That we will never meet again In this lifetime/So let me say before we part So much of me/Is made of what I learned from you"
