"...breaking into song for no apparent reason other than no one's sung in two whole minutes."

That sounds an excellent sort of reason to me.

I used to watch a lot more TV. I've even got a little thingy on my computer that lets me watch while I'm on the net. But when I start using it, a break comes in the programme, and I move over to the Mudcat; and more often than not the stuff going on here is better than what's happening on the box, and I switch it off. (When you're watching the TV and you find yourself saying "That's rubbish what you said" or "Right on!", nothing comes back; but here someone's bound to argue the toss with you.)