What's the deal with Lotte Lenya's appeareance in these lyrics? She's a real person, an actress, whereas (I assume) Suki Tawdry, Lucy Brown, Louie Miller and MacHeath himself are ficitonal characters.

The recently deceased Jerry Orbach's first job in the New York theater was a minor role in The Threepenny Opera. Before long, he was "promotyed" to the major role of Mack, and (according to his AP obit) he played opposite Lotte herself.