I suppose it says that people don't typically become 'enlightened', in the Buddhist sense of the term, by listening to music.
I think that the Pali canon discouraged making happiness dependent on sensual conditions (e.g. "I would be happy if only I were listening to a symphony", or "... a better symphony than this one", or etc.).
I saw a movie once (probably Amadeus) where the composer says, "You lucky people: God loves you, and I'm about to prove that to you." Such "enthusiasm" might be admirable but it seems to me a fabrication (inventing a 'God' and so on to explain sense-input).
On the other hand there are some Arts which are traditionally or culturally associated with some forms of Buddhism: for example Bokuseki. I don't know about that, I guess from my reading that's supposed to demonstrate a lack of defilements/hindrances in the author's mind, and to be a visible (informative) record/remainder feedback/learning tool of something (i.e. of the author) which really happened.
My take on it is the Pali canon was like,
- You're supposed to be monks, not spend your time and indulge your desires by sneaking off to listen to music festivals
- Arahants and non-returners are above/beyond a craving/thirst for music (i.e. sensual desire)
- Lay people who want to be like monks and arahants, who want to sip from the experience which monks should aspire to full-time, ought to put aside their craving for music at least on holy days
I read a non-Puritanical attitude into this answer though, e.g. you wouldn't despise a lay person for liking music,
If someone really has no problems, that's great, they are Enlightened! The historical Buddha (According to Stephen Batchelor's retelling) said as much on his death bed, when he asked if anyone had any questions left, no one did, so he said, well you all must be enlightened then. People need Buddhism when their current raft has sunk. If there is food on the table, a comfortable place to sleep, and they have no complaints about their daily routine, then our jobs as Buddhists is to rejoice in their success (mudita).
What should naturally creative people do with themselves?
I'm sorry, I don't know doctrine about "creativity", whether natural or otherwise.
The impression I get (from the Pali suttas, summarized in a book titled The Buddha's Teachings on Prosperity: At Home, At Work, in the World) is that what lay people "should" do is behave as good and responsible members of society -- i.e. practice "ethics" or virtue.
The book includes advice (quoting various suttas) on how to handle wealth, marry, be a parent, and so on.
One of the suttas mentions "six directions" i.e. each person's responsibility towards their parents, teachers, spouse and family, friends and colleagues, workers and servants, and "ascetics and Brahmans".
When you make money it recommends re-investing some, saving some, and using only a portion for your needs. It recommends wealth without squeezing others (like a bee collects honey without harming the flowers) -- and so on, the whole book contains instructions like these for lay people.
The canon does warn against an excess of partying, immorality, for example,
And what six ways of squandering wealth are to be avoided? Young man, heedlessness caused by intoxication, roaming the streets at inappropriate times, habitual partying, compulsive gambling, bad companionship, and laziness are the six ways of squandering wealth.
Buddhism also recommends Dāna (generosity or charity: especially giving to monks, spiritual people).