Tom, do you mean the one Gaberlunzie recorded? You can find it at My Songbook
Good thing I checked - Henry doesn't seem to have got round to R yet, so here are the words you (hopefully) were asking for:

REMEMBER JOHN McLEAN
(John McGrath)

Chorus:
What freedom you call is not freedom at all
Till tyranny is done
Not the English alone but the tyrants at home
Must go before we've won

You working men of Scotland, all you who want her free
Remember John MacLean right well, or free you'll never be

What good your flags and banners, what good your Bannockburn
When Scotland's full of money-men who will rob you in their turn

We'll proudly build our Scotland where landlords' fences fall
Where industry's for you and me, where each can work for all