I may need more than 'the drift, ' Richard. It sounds like you are in a quandary about what is legitimate, and how important originality is. But that's just 'the drift' that has drifted to me - maybe I'm off.
First, content is not 'used.' And a written piece's chances for greatness are not something that can be formulated in advance. It's good or it's not good, and you only know this in retrospect. No one ever sat out to write a great poem, not even Milton. well, he did, but he wasn't a sure thing.
I refer to something called 'original sin.' Paul McCartney,20 years ago, when Lennon was shot, composed a song called 'Here Today, ' which he revealed was the first song he had written since Rubber Soul which used the same orchestration as another of his songs. He was so neurotic about 'originality' that he deliberately chose different production schemes for every single song.
(The song was an imitation of 'Yesterday, ' which it echoes in various ways.)
My friend Skadi meac Beor looked askance two weeks ago when I joked here about 'marketing a poem' - pointing it toward success. That was supposed to be satire. In truth you can deliberately do all sorts of things -like Macca did - but the art of the thing will likely be something you didn't scheme. With him it was always melody and great bridge-sections.
As a longime 'originalist' - always looking for soemthing no one has thought of before - I am moving steadily toward the notion that great art is usually a kind of folk art - it is something that people understand in an instant, because it is rooted in commonplaces.
It's why we still read Bobbie Burns, whose work is rooted in the known, but John Ashberry, a wonderful originalist, or Bill Knott, ditto, must inevitable fade away.
This is good news for hobbyists, because they are likely to be closer to folk forms than artists on foundation grants, pursuing esoterica.
Anyway that is my prejudice - it is consciously anti-elitist and anti-gnostic. If a 12 year old C student can't get a thing, it's probably not worth getting. Wortse - you may create a mini-cuture of other bright people who say they get you, but they hjave to say that, because they want you to get them. Which is approximately the art world today.
It will be interesting 50 years down the road, to see what people will like from the Beatles' (for instance) career - the really clever stuff from the White Album - or the hand-clapping skiffle tunes from their Cavern days. I'm thinking, the older songs. 'I am the Walrus' will probably not make it into the canon, but 'I Saw Her Standing there' will.