Create page slug from two fields

You can use a page model together with the plugin for the subpage in which your override the create method, example:

use Kirby\Cms\Page;
use Kirby\Toolkit\Str;

class ReleasePage extends Page

    public static function create(array $props): Page
        $props['slug'] = Str::slug($props['content']['title']);
        return parent::create($props);

If you use a structure field for the artist, then you won’t have a single artist, though, and would have to make sure to fetch the first or so…

Make sure to require the artist field in the add dialog to make sure you get the desired results.