The Monday before Johnny went to Poland I sang "The Old Sow" at Herga. My mother had taught it me and /she/ could whistle using fingers, a trick I've never managed. The song demands a good, loud whistle so I use one of those siren whistles.
My version is a bit different to that in Digitrad:
There was an old farmer, 'e 'ad an old sow
[FX: snort] ow
[FX: raspberry] ow
[FX: whistle] idle dee dow

At the end Johnny announced with that twinkle in his eye that he thought it'd be much better if I just used the whistle and left out the words.

chris :-)