"Mack the Knife" is a popular song from the 1928 Brecht and Weill musical "The Threepenny Opera." The song introduces the character Mackie Messer, a charming yet ruthless criminal known for his violent deeds. Its catchy melody and dark lyrics highlight the contrast between his appealing persona and his sinister actions. Over the years, "Mack the Knife" has been covered by numerous artists, including Louis Armstrong and Bobby Darin, contributing to its enduring popularity. The song's themes of crime and morality resonate with audiences, making it a classic in both musical theater and popular music.