Probally unkown to most of you, but this is one of the big revolutionairy tunes, essential in the development of modern bass driven music like UK dub, dubstep, jungle, dnb and so on. It's also a big influence in all electronic dance music.
It's a dubplate remix (unique remix for one dj) of an song called "Beware" by the jamaican reggaeband Creole, made in 1975 for the legendaric jamaican/british soundsystem (dj) Jah Shaka, the godfather of electronic dub. This tune is remixed a zillion times in the meantime, but this is the original music that started that bass driven music. There was a lot of dub made before (since 1968) but none hit this hard as this dubplate remix and made such an impact on modern music. The dubplate was released for the public 20 years later only. Until then you could only hear it when Jah Shaka played.