What is this song I heard at Oktoberfest?

Hi all,

I heard this song in one of the tents at Oktoberfest and I liked it a lot. Being an American, I’ve never heard this before. I tried asking people around me what it was called and no one could say the name, only that it was a popular German song.

It sounded like everyone was singing “la la la la la la la” to the rhythm of the music.