or, Strategic Harmony Interference Elimination and Lead Defense.
Guitar pickups are electro-magnetic transducers that use changing magnetic fields to induce pulses of alternating current electricity from a coil of copper wire at voltages reproducing audible sine wave frequencies in relation to an absolute ground. I think. Sometimes I prefer the definition as proposed by Messrs. Dope and J; magnets are a “miracle.” Unfortunately, the latter definition does nothing to help understand why my bass might be buzzing like a bee chainsawing an alarm clock when the FOH sound guy turns the lights on and off. There’s two ways to solve the problem. One, you can learn to play the chainsaw.
Or two, you can shield your guitar. Truth be told, it should probably be shielded from you: throwing it around, spilling beer on it, bleeding on it… and by “you” I mean “me.” But the shielding I refer to will protect that precious guitar signal of malodorous melodies from the buzzing bullshit of the outside world.