This is interesting, but being a fan of Brahms, I want more details:Orchestra brawl: Fistfight in elite seats stuns symphony patrons
So exactly what part of the 2nd movement did this happen during? The music evolves through a remarkably wide range of moods, from ethereal to agitated to apocalyptic. Only an utter clod could start a fistfight during the opening theme of that movement. Later on, though, it could actually have been pretty well synchronized with the music. But the article suggests that the fight broke out during a quiet episode.
I wonder what classical music would be most likely to provoke/inspire/accompany fistfights? There actually are a lot of pugilistic moments in the Brahms symphonies.