Joined Cases 55 and 57/80, Musik-Vertrieb Membran GmbH and K-tel International v. GEMA. Preliminary Ruling of 20 January 1981 requested by the Bundesgerichtshof - Common Market Law Review View Joined Cases 55 and 57/80, Musik-Vertrieb Membran GmbH and K-tel International v. GEMA. Preliminary Ruling of 20 January 1981 requested by the Bundesgerichtshof by - Common Market Law Review Joined Cases 55 and 57/80, Musik-Vertrieb Membran GmbH and K-tel International v. GEMA. Preliminary Ruling of 20 January 1981 requested by the Bundesgerichtshof 18 3 Common Market Law Review