1. Member States shall ensure that, in the absence of an applicable collective bargaining agreement providing for a mechanism comparable to that set out in this Article, authors and performers or their representatives are entitled to claim additional, appropriate and fair remuneration from the party with whom they entered into a contract for the exploitation of their rights, or from the successors in title of such party, when the remuneration originally agreed turns out to be disproportionately low compared to all the subsequent relevant revenues derived from the exploitation of the works or performances.