I bought a CD of the Broadside Band playing Playford and found a tune "Lady Catherine Ogle" on it. The last lines of the A and B parts of the tune fitted the line "Johnny had gone for a soldier" so well that it lodged in my brain for so long that I ended up writing the following to it:

At break of day on the on the King's Highway,
As we were marching o'er hill and dale,
I met a fair maid and she did bewail,
That her Johnny had gone for a soldier.

I says to this maid, "Come sit upon my knee,
Under the shade of yon spreading old oak tree,
And I'll tell to you of the deeds that were done
By them that have gone to be soldiers."

CHORUS: We marched on our way o'er the King's Highway,
To the fife and the drum, but what shall become,
When the bayonets slash and the bullets crash,
Of them that have gone to be soldiers?

She sits on my knee underneath that big oak tree,
And I kisses her and she kisses me,
And then I shows her the things to be done,
By them that have gone to be soldiers.

Then up says this maid what shall become of me?
For I have lain with you underneath that big oak tree,
And I says to her, "Why don't you follow me,
And share the life of a soldier?" CHORUS

Now long years have gone and the wars they are all done.
I no longer march to the fife and the drum;
But the maid has stayed with me and she never rues the day
That she went and she followed a soldier. CHORUS TWICE