Auld Lang Syne

That weird song nobody knows the words to is a song in the episode "More of the Same". Robin gathers Starfire, Cyborg, Raven, and Beast Boy in the Titan Tower's bathroom to orcastrate the song. The four Titans sing timidly not knowing what they are doing, and Robin eventually takes over singing it himself.

Lyrics
Starfire, Cyborg, Raven, and Beast Boy: (Singing auld lang style timidly)

Robin: (yelling) That's not how the song goes!

Cyborg: (talking normally) No one knows the words dude!

Robin: (talking normally) Well, I do. Now, sit back and listen to these bittersweet lyrics.

(Clears throat)

(Singing auld lang style)

Raven: (talking normally) Wow... I liked our version better.