Jim,
You mentioned back up the thread something about me not being able to provide info on 'Bonny Bunch of Roses'. I have that info at hand at the moment if you still want it.

Meanwhile let's take the most prolific of all ballads 'Barbara Allen'. Most of the Child Ballads are not relevant here because less than half have been found in oral tradition in England, but this one is useful enough as an example. Its earliest manifestation is on a 17th century broadside and it existed in multiple forms in print ever since. Okay so you say it could have come from oral tradition. About the same time, it was being sung in a high-class theatre in a concert in London. Now I don't know about you but I can't see these highly sophisticated people going out into the countryside or anywhere where peasant songs might exist to learn songs to sing on the stage.