Note: it is perfectly good English to say that someone 'appeared on stage' at a particular theatre, meaning that they 'performed on that stage'. Of course, in this instance, the verb used translates as 'performed', but to my English brain, it was also acceptable to use 'appeared'.
The audio is wrong. ... Har du optrådt på den scene. In the DUO audio the stress is put on scene. That is wrong. You should say... Har du optrådt på dén scene. As DUO has pronounced it it could be misinterpreted as if the person (you) had performed on the late (something). It does not make sence, DUO.