"The thing-- Oh!" Stacia laughs. "Okay, so, in addition to memorizing songs and writing the notes out on paper, people have figured out how to etch objects so that when you run a certain tool over them, they can play music without the instruments or performers being anywhere nearby. Normally people record the sounds of both the instruments and the singer's voice, but karaoke machines just play the instrumental part, and people like you or me are supposed to perform the singing part. And a lot of people aren't nearly as good at singing as professional performers."

She grins. "They probably say it's bad for morale because someone is really bad at singing."