You can take what some might think to be the crassest, most banal musical guff in the world, and many people may well be inspired by it to learn an instrument because of hearing it.

True, and 'active' vs 'passive' probably isn't the best way to describe the difference between recorded and live music. It's still a pretty big difference.

Suibhne:

Someone singing a song or playing a tune is one form of playing back a musical recording; they've gone to trouble of learning it, and each time they'll sing it will be to the best of their ability

And, as you've said yourself in other threads, each time they sing it it'll be imperfect, and each time they sing it it'll be different. Those differences & imperfections are precisely where the folk process gets started, if it can.