Here is Ella Fitzgerald singing my favorite rendition of "Mack the Knife." She forgets the lyrics less than 2 minutes into the song and improvises the rest of the way. Her lyrics are clever and hilarious at times. She also impersonates Louie Armstrong. One more example of her greatness. I love Ella.
Tacked on to the end of the video is a 1930 version of the song in the original German from the "Three Penny Opera" by Kurt Weil and Bertolt Brecht.