The Chasm Between Comedy And Music

Why is it that karaoke machines only have songs on them? If what they do is take a version of a public performance and allow the rest of us to give our own interpretations of the material, why aren't there other options, like the "you talkin to me?" scene from Taxi Driver, or Martin Luther King, Jr.'s "I Have a Dream" speech. Jonathan Goldstein and producer Starlee Kine find out why when they go to a karaoke club that has, along with all the songs, comedy routines for people to perform. (11 minutes)