I was comparing the stayability of folk song to the mayfly length existence of your average pop number.

And yet... would anyone know about these durable old warhorses had there not been a revival driven by a diligence of collectors working against the clock convinced of their imminent demise? And what of Jim Carroll's tales of whole communities of hoary old tradition bearers giving up on the old songs overnight soon as they found something better to do - i.e. watch TV like any other sensible human being?

Pop's durability is as an Idiom - as such it grows and changes and shoots off in ways no one can readily predict as it sheds and dates deliciously. We're immersed in METRONOMY right now; hadn't even heard of them a year ago, now their exquisitely crafted pop perfection embodies many hundreds of years of evolved cultural process - certainly to my jaded ears anyway.

As Moondog might have said (but never did):

The mayfly flits fleetingly in the spring sky then dies -
Thus billions of years of loving life unfurl before our very eyes!