Pink Floyd can sob 'till the cows come home, but it's not going to make me believe that <del>he's</del> they're entitled to money for something <del>he's</del> they've already done.
It's true that musicians sort of used to be paid up-front, in the traditional label model where a record company gave a musician a big advance to make an album, and then pocketed most of the actual profits from the sales of that the album (akin to hiring an engineer to build a bridge, then collecting tolls on that bridge). But that's no longer the model for most up-and-coming independent artists, and in any case, that just shifts the royalty-collecting burden to the record companies, who still need to be able to recoup their initial advances.
Another approach, which works well for bridge-building, is that the government just pays some engineers to build a bridge, then lets everyone use the bridge for free. This is like the really old school practice in which a wealthy prince commissions Beethoven to write a string quartet, and once complete that string quartet is then freely available for anyone to perform. As a model for music in the modern world, this would mean socializing the music production business, i.e., taxing everyone the price of a Spotify subscription and pumping that money into NEA grants for artists to record new music, which would then be free for everyone. On the bright side, this would eliminate all worries about piracy and chilling effects from anti-piracy enforcement. But there are also lots of drawbacks, e.g., in this model the decision as to what music should exist would be made, not by the market (as in the indie model), or a profit-oriented record company (as in the label model), but by government bureaucrats whose incentives come from the political process. Of course this could have some good effects (maybe they'd fund fewer Justin Biebers) but IMHO there are serious problems with a system in which an artist's viabilaity is contingent on their staying in the good graces of the government.
Also, just so you know, Pink Floyd is a band, not a person.
In any case, I don't think it's clear that government needs to be involved at all. While patronage might have been the realm of elites in the middle ages, in the modern era any group with enough members can easily become a patron with small cost to each for the sake of supporting any artist deemed worthy (obv. crowdfunding, etc.).
It might take government to tunnel under the English channel, but it doesn't take government for a bunch of neighbors to get together and pave their lane. And supporting artists is much more the later than the former.
If you get hired to create music, there's a fair chance nobody will ever hear it. (Other than your mum).
I can't see how we could possibly pay musicians up front.
Your first sentence betrays a similar lack of understanding about how royalties work.
And bridge-building.
And doors.
And to tomn's credit, the lyric is a bit more relevant than just some random line: The root poster thought Pink Floyd was a person not a band. Apparently that's a common enough misapprehension that they mentioned it in a song... thence the quoted lyric.
Royalties make sense for music, books, movies, and such because at the time they are produced we have no idea how much value they will provide. A song that is mildly popular and then disappears provides less value to the public than a song that becomes an enduring classic that is listened to for generations.
Please support that argument with evidence.
I need to act on the plan to go to the symphony more, while I still have the chance. Symphony orchestras would be in trouble even without the internet; they're very expensive, since they're collections of dozens of trained professionals who have ever-fewer daytime gigs.
Alas, recordings are nice but don't really do an orchestra full justice. Real instruments have real timbre. And, of course, even the recording would be lousy were it not for highly trained and rather expensive studio and mixing engineers.
How about poetry? Performance art? Pantomime? Dance? Standup comedy? Etc.
As for what which arts have value, I think the costs have little to do with that. There are art projects that cost millions that I think are shit, and there are street musicians who can barely buy a deli hero who I think should get million dollar record contracts.
Bridge engineers and architects are good economic substitutes for each other. You can put out an RFP and get competitive bids back.
I for one really like making something of value for people and continuing to get paid for it as long as people get value out of it.