What would your favourite pop videos sound like without the actual music?
Not great, probably. But sound designer Mario Wienerroither strips videos of their music tracks and then goes one step further - he adds in funny effects based on the on-screen action.
His music-less version of the Britney Spears song 'Oops! ... I Did It Again' has been viewed more than 3m times on YouTube.
He gets around copyright laws by saying his videos are parodies - and he says he doesn't make any money from them. BBC Trending had a chat with Wienerroither - and we had a go at making a music-less video of our own.
