If I shulde deye bi this day - me liste noughte to loke;
I can noughte perfitly my pater-noster - as the prest it syngeth,
But I can rymes of Robyn hood - and Randolf erle of Chestre,
Ac neither of owre lorde ne of owre lady - the leste that evere was made.
Piers Plowman 1377

Good point(s) Steve. But the lack of surviving early versions does not mean they did not exist in oral circulation - true, many of the 'traditional' ballads we now have derive from printed broadsides and chapbooks. However, there is no doubt that some of these songs and ballads(esp of Robin Hood) were popular at least as far back as the 14th Century, there are numerous references, but very few original texts.

Whether the were spread via 'Oral Tradition' as driven by minstelry or just plain folk, will probably remain a mystery. Generally they were only written down for the literate - which meant the gentry or the clergy (the latter usually railing againts them!).

Myself I would doubt that any 'ordinary' person really knew all of 'The Gest' (all 457 verses), but we know from extant oral traditions that people can memorise huge amounts. Me, I'd like so see them try after a few pints of scrumpy!

Two of the earliest examples of Robin Hood ballads:
Robin Hood and the Monk 1492
A Gest of Robyn Hood Child: 117, (Wynkyn De Worde edition dated somewhere between 1492-1534)

I do need to get out more.