A guitar technique. In order to play a pinch harmonic you have to change the way you hold the pick. Hold the pick with your thumb close to the point, close to the strings. Change the angle of your downstroke so that the pick edge hits the string. Don't play the pick parallel to the string like you usually do. Angle it down on the front side. When you pick down, twist the pick down on the front side and let your thumb hit the string just after your pick does. If you get a ringing normal note, that means you need to add more thumb. If you get a "thuk" sound, you are using too much thumb. Practice until it works.