Sharing files between pages & linking them via 'pages' field

The CMS Questions
20

that won’t work because the query language doesn’t support evaluating function arguments.
Your query is automatically converted to the equivalent of:

site.find("releases").children.getRecords("page")

(page is simply seen as a string and not as a variable pointing to your artist)

There are many ways to work around this.
I guess the cleanest and most expressive one would be to create a page model for your “artist” pages.
That would go like this:

/site/models/artist.php:

<?php

use Kirby\Cms\Page;

class ArtistPage extends Page {
  function getRecords($recordsId) {
    return site()->find($recordsId)->children()->getRecords($this);
  }
}

you would use it in your artist.yml like this:

        sections:
          releases:
            headline: Releases
            type: pagesdisplay
            query: page.getRecords("releases")

If you only ever will have a single page that collects all records (and that one will never change uid), you might as well hardcode the path to it:

<?php

use Kirby\Cms\Page;

class ArtistPage extends Page {
  function getRecords() {
    return site()->find('releases')->children()->getRecords($this);
  }
}

and then simply use it as query like this:

query: page.getRecords

you can of course use that function also in your artist template ($page->getRecords())

PS: I haven’t tried any of that code.