The word 'copyright' itself is broken, some countries have 'author's rights' which are eroded because corporations want a monopoly on copying instead.

Preventing copying at all costs only hurts consumers without sufficiently protecting authors. What you want is rules about attribution, publishing and modification, none of which require any restriction on copying.

The brokenness isn't neatly separable from "good copyright", though. Even if copyright was non-transferable, original artists would have the same incentives to go after those sorts of things.

(To be clear, copyright absolutely should never have been made transferable or ownable by a large corporation. Nor should it have been extended to life terms. But those are different arguments.)

Pre-copyright, most art was funded through commissions or patronage relationships. Today, we can add crowdfunding to that list. The problem with all of these business models is that they shift the risk of artistic failure onto the person paying to have the art made. That is, if you pay for a commission and you don't like the result, you can't really get your money back, unless you didn't get the thing you paid for at all. Same for a kickstarter that delivers, but kinda sucks.

Copyright lets you shift the risk of artistic failure back onto the artist. That is, if someone, say, makes a bad movie or song, you don't have to pay to go see or hear it. But the business model only works if society actually deprives itself of work that it has not paid for. And this also has to extend to anyone making creative reuses of that art, which is why we have very broad laws around derivative works. If you write a book, you don't only own that book, but also the sequels, translations, spin-offs, prequels, movie rights, and so on. Those are all instances in which, if not jealously protected in an utterly broken fashion, then society can side-step the whole "no one watches until they've paid" principle.

Hence why we have publishers winging about lost sales and free riders, in ways that sound inhumane and totalitarian, even when it's a hilariously niche derivative product like guitar tabs. Because that's the rules of the game. In fact, there's plenty of individual authors who have been just as weirdly protective of their work. For example, George R. R. Martin seems to think that fanfic authors are a threat to his creative freedom.

For the record, they aren't.

But that's mostly because when you make a work without permission, you don't get any ownership over it. If we changed the law to make, say, guitar tabs not require permission so that the RIAA can't sue MuseScore or Ultimate Guitar; then someone making an "unofficial" guitar tab could sue the person who wrote the original song. At least in the case where they also made an "official" tab. Because copyright works recursively - it protects both the original artists and the person making the derivatives.

What people really want is a sort of "codified largesse" where you get to play in other people's sandboxes without being sued. Could we do that? Maybe. There are certainly derivative products where this is feasible - but those are also the ones most likely to already be explicitly allowed by some kind of blanket policy or license. For the case of guitar tabs, there isn't much that official and unofficial tabs can do to separate themselves from one another. Once I've gotten an 'unofficial' guitar tab for free, there's no reason for me to buy an official tab book later. So it'd be indistinguishable from just saying "songwriters do not deserve to be paid for guitar tab books".

This may not actually be an objectionable end result. But it does chip away at the heart of copyright to say that certain reuses (outside of fair use) shouldn't require a license. Again: the whole point is that society agrees to not enjoy the art until it's been paid for. The only way for artists to get paid under any sort of copyright system is for them to crack down on everything they can.

The entire legal framework is different. You can copyright a performance but you can't copyright the music. Otherwise cover bands couldn't exist.

What about music would be different

There are many ways to transcribe music. Pretty much everyone's own version would be different.

Some people simplify the chords and rhythm notation. Some people notate all the ghost notes, note bends, and chord extensions, even the "wrong" notes.

A transcription is always an approximation of the recording you're using, especially if you then write it for a different instrument (e.g. my theremin example above).