In 1960, Mack the Knife was a relatively new song and people loved it. So on a whim, Ella added it to a performance she was doing in Berlin. The trouble was that she didn't know the words very well and about halfway through had a lyrics train wreck. If this were any other singer in the world, this would be ugly. However, when Ella forgets lyrics, songs actually get better. Don't believe me. Check this out.