Natural harmonics are one of those techniques most guitarists discover by accident. Your finger grazes a string at the wrong spot, and suddenly something pure and bell-like rings out.
Artificial harmonics solve a problem that every guitarist eventually runs into. You love the shimmer of natural harmonics, but they only land on fixed pitches determined by open-string physics.
Pinch harmonics create one of the most recognizable sounds in rock guitar. Most players who want them assume they need a specific pedal or amp setting. Not so!
Harp harmonics are one of those techniques that stops listeners cold. You play a simple melody, and suddenly the guitar sounds like three instruments at once.