Continuing this discussion as an addendum to my late Bard post, I had mentioned that there was a problem with the audience or beneficiaries of artworks that have been produced. I'll tackle this now.
See, we can talk about the bard creating art and suppose the party picking up a little experience here and there as the party's bard gets lucky with doubles, but we have a greater question. What is to stop the party from simply entering a large city, visiting the local gallery and soaking up all the plentiful x.p. that's already been produced and is hanging on the walls there? Or literally paying for experience by coughing up the entrance fee for the Cirque du Renaissance that happens to be showing at a Burgundian or Florentine fair? See a few jugglers, attend a play and a concert, walk past a few swirls of paint and go to bed a 5th level fighter!
I won't deny it, that is a problem.
Let's consider some solutions. The first and most obvious one is access. 17th century French salons, at least, were not open to the common hoi polloi. A vast majority of people ~ player characters included ~ can't read, leaving off a fair number of great works in the way of poetry and prose. The very best pieces of pottery, jewellery, sculpture and such never make their way into the public markets and are often made for private appreciation. Galleries, as we understand them, were a somewhat later invention than the 17th century and this, at least, can slow down a few visitors. The Louvre in my game will still be a palace until 1692 and won't be open as a gallery until 1793, after the French Kings are gone.
This doesn't discount everything, however. Crecy, Chartres, Lincoln and hundreds of other cathedrals are still quite evident and plain to be seen by most of the population, as are the Pyramids, the Hagia Sofia, the Taj Mahal and the many parts of the Great Wall of China. Musicians may play for monarchs but they don't play exclusively for monarchs, so that even the greatest musician in the world may happen by to play for a bed that night. Circus performers, puppeteers and dancers are quite public performers and we all remember being told about the groundlings at Shakespeare plays. There are still plenty of opportunities for free x.p.
However, comprehension does limit this somewhat. I described the limits of how much understanding a lower level has in art created by a higher level bard when I first proposed the art-as-x.p. transfer idea. Perhaps we might install a different limitation, however, in the way of intelligence and wisdom checks, so that our munchkin fighter of the 8 intellect can't help but fall asleep as Hamlet talks to his dead father.
But that doesn't help us with mages and clerics, does it? And the last thing we need is to give mages and clerics an edge - they get enough as it is. So perhaps checks aren't such a good idea.
Well, how about fatigue? How many paintings can a person stare at? How many circus performances and poetry readings can a person reasonably be expected to endure? Perhaps that first bard might get the blood pumping and flowing, but after the one after, or the one after that? We might say that if we grew up in the vicinity of Notre Dame, who really cares what it looks like to outsiders.
On the vein, perhaps there's only one kind of art that can appeal to a given person. You might like art pottery but floor mosaics are a yawn. Perhaps its music that steals your heart and you feel nix, naught, nothing for what others call a good dance routine. Perhaps all this other stuff just doesn't reach you - but give you the death-defying, flabbergasting demonstration of a high wire act and your day is made.
Finally, there is always scarcity. The players may go looking for these things but the reality is that they're just damn rare. Or surprisingly lacking in the promise that others have given. Perhaps the Pyramids really are just piles of rock. Perhaps the Taj looks great in a rendering, but since the grounds weren't finished until 1653 (the Mausoleum was finished in 1643), perhaps it is less than great when surrounded by thousands of slaves ripping up the earth in every direction. Perhaps the Great Wall is just a wall.
I think it is probably a combination of all these things - along with every dirty trick I can invent to turn seeing a single painting into a difficult, trying adventure that makes the pay-off cost something. Certainly, having created the problem, I'm on the hook for managing the solution in a reasonable, player-accepted manner.
Else I'm stuck with players easily piling up unbound amounts of experience, which certainly doesn't work for my game.