Barney's auto-cue/teleprompter question. what the heck?

What exactly IS on Barney's teleprompter anyway? Other than lyrics. Does it also include guitar notes and banter/joke lines or something, too? Always been curious as he looks at it sometimes even when just tuning the guitar.

There was once a quite large sum of money maybe £200,000 for a Sunkist ad if I recall... so who knows what might be on there.

I don't understand how he didn't see what Hooky had sprayed on the equipment presumably behind him, if he turned round surely he would notice it immediately? Did he not look around? Did no one notice? Maybe the lights are too dazzling. Dunno.

During Blue Monday I believe it's Coronation Street on catch-up.