A band of young musicians will do the impossible to boycott a song they didn't like that's supposed to represent Spain in a famous musical contest.
| Actor | Role |
|---|---|
 José Luis BorauTio Prudencio | Tio Prudencio |
 Antonio DroveAntonio | Antonio |
| AAntonio GassetNot listed | Not listed |
 María IsbertIsberta | Isberta |
| MMercedes JusteJusta | Justa |
 Ramón PonsGasset | Gasset |
 Patty ShepardPatty | Patty |
| JJudy StephenJudy | Judy |
 Tina SainzTina | Tina |
 José María ÍñigoRosco / Himself | Rosco / Himself |
| IIsabel OrtegaNot listed | Not listed |
| SSusana MorleyNot listed | Not listed |
| AAna María MoralesAmiga de doña Laura | Amiga de doña Laura |
 Vicente BañóPresentador TV | Presentador TV |
| AAna María MendozaPresentadora festival Mundocanal | Presentadora festival Mundocanal |
| FFernando de AnguitaNot listed | Not listed |
| CClara MartínezMujer que pide discos de horóscopos | Mujer que pide discos de horóscopos |
| CClara BenayasMarina de Obregón | Marina de Obregón |
 Jaime ChávarriSpot Producer (uncredited) | Spot Producer (uncredited) |
 Elena SantonjaParty Guest | Party Guest |
| GGloria Van AerssenParty Guest | Party Guest |
 Iván ZuluetaSpot Director | Spot Director |
| CCarlos GarridoCarlos | Carlos |