PEEX - make your own mix at a concert

At Elton John’s final tour the audience can use a device called PEEX which allows them to mix the instruments the way they like. Individual instrument tracks from backstage are transmitted via radio signals to PEEX and then synchronised with the sound being sent - meaning there is no delay. Audience members can then mix the music on their smartphones in real time, allowing certain instruments or vocals to be made louder than others, BBC reports.