The show is performed by a single puppeteer inside the booth, known since Victorian times as a "professor" or "punchman", and assisted sometimes by a "bottler" who corrals the audience outside the booth, introduces the performance, and collects the money ("the bottle"). The bottler might also play accompanying music or sound effects on a drum or guitar, and engage in back chat with the puppets, sometimes repeating lines that may have been difficult for the audience to understand. In Victorian times, the drum and pan pipes were the instruments of choice. Today, most professors work solo, since the need for a bottler became less important when street performing with the show gave way to paid engagements at private parties or public events. In modern shows the audience is encouraged to participate, calling out to the characters on the stage to warn them of danger or clue them in to what is going on behind their backs.