What's The Name of That Song

It is a classic Bert and Ernie skit from Sesame Street. Ernie wakes Bert up because he has a song stuck in his head and can't remember the name of the song. Then they sing "La-de-da-de-da La-de-da-de-da, What's the name of that song". Then Bert has the song stuck in his head and can't go to sleep.

Well the same thing has happened to me. No, I don't sleep in the same bed as another dude, I have a song stuck in my head and I don't know the name of the song, or who performs it. It is an instrumental funk song from the 70's that I hear all the time, but they never tell the name of the song or who performs it.

Doo-du-lu-doo Doo-du-loo-doo Doo-du-lu-doo-doo-doo-doo Doo-du-doo-doo, What's the name of that song?

Please tell me the name of the song and who performs it.