The EU's "bestseller clause": your right to fair pay, yearly statements and a second negotiation
Articles 18 to 22 of the EU's 2019 copyright directive give songwriters and performers a right to proportionate pay, a yearly report on what their work earned, a claim for more when a deal turns out lopsided, and a way to take back rights that sit unused. The rules are real, but each country wrote its own version, and most of it only works if you ask.
Artist rightsvia EUR-Lex, Publications Office of the European Union