Mahna Mahna I Don’t Always Mahna Mahna But When I Do Doo Doot Doo Shirt! The Muppet Show’s and Seseme Street’s, Mahna Mahna. Ever since I saw The Muppets a few weeks ago, I have been unable to get the Mahna Mahna song out of my head. It plays on a continual loop within my brain. It’s the perfect song! It could go on forever if you wanted it to. The words are so easy to remember, Mah-na and Doot. However, this was not always the case. Most people know the song from its different appearances on The Muppet Show in the 1970s. We’re all familiar with it. It’s like an old friend.