The version of this song that I know is almost exactly that in the broadsides in Malcolm Douglas' link, with a slight difference in the first verse:

You gentlemen, both great and small,
Gamekeepers, poachers, sportsmen all,
Come listen to a simple clown,
I'll sing you the death of poor Bill Brown,
Come listen to a simple clown,
And I'll sing the death of Bill Brown.

the last line serving as chorus until the last verse when it becomes:
"And I've sung the death of Bill Brown".

Walrus