Well, get this, it uses the Fourier transform, a mathematical technique for breaking down a signal, for instance, a song into its frequencies, like taking the bass guitar out of a song.
Cables and the affects pedals. I use some affects to change the sound of the bass guitar when I'm playing and so I just bring that and plug it into the live house bass amp that's there.
Sergeant Pepper was the first album released after the rumours, and people claimed the sleeve art included suspicious symbols like a flower wreath on the ground, shaped vaguely like a left-handed bass guitar.