Thanks for the info folks! It was my little brother Neil who started it off, actually. (He plays the saxophone, poor deluded lad; but he's family, after all.) Eve since he was a little boy, he's looked up to me to answer all those questions he can't answer for himself, like "where do the flies go in winter?" and "when are you going to buy a round?". So naturally, when he came up with yet another daft query, he turned to me; and rather than say, "how should I know?", I thought I'd ask my Mudcat friends in the sure and certain knowledge that they'd be able to tell me, and keep up my dear little bro's touching faith in my omniscience. I know it will make his bleary little eyes light up when I pass this on to him (even though it hasn't quite provided the answer he was waiting for).
You'll know how sincere I am when I say "thank you, Mudcatters" from Neil and me.