John,

The version I know can be sung to the tune "Lincolnshire poacher", and where the lyrics say *** the performer knocks on something 3 times - guitar, chair, whatever. The last line of each verse is usually repeated too.

The dogs they had a concert, they came from near and far,
And some they came by aeroplane, and some by motor car,
Before into the concert hall they were allowed to look,
Each dog had to take off his *** and hang it on a hook.

No sooner were they seated there, each mother, son and sire
Than a dirty little yellow dog began to holler "Fire!"
Out they rushed in panic, they didn't stop to look,
Each dog just grabbed a *** from off the nearest hook.

So that's the reason why you see on walking down the street
Each dog will stop and swap a smell with every dog he meets,
And that's the reason why a dog will leave a good fat bone
To go and smell a *** in hopes to find his own.

I have also heard it recited instead of sung, and the word arsehole is used instead of the 3 knocks.

Have fun!
Cheers
JennieG