Imagine having to make objective decisions in a match where the noise is louder than an aircraft taking off - as was the case when former Barca hero Luis Figo returned to the Camp Nou with Real in 2002.
That match became infamous for the missiles thrown at the Portugal star, dubbed a 'money-whore' by his former devotees in Catalonia; missiles that included money, whisky bottles - and a pig's head.
The referee that day was forced to take the players off the field for their safety, with Barca captain Carles Puyol and team-mates returning to try and calm their supporters down.
The enmity between the historic rivals spiralled from the moment in 1953 when Alfredo Di Stefano controversially signed for Los Merengues after initially agreeing to join Barca. The Catalans claimed dictator General Franco tipped the balance Real's way...
