A harmonic is a tone that’s created by the guitar by touching the string above a fret on an open vibrating string. There are 2 types of harmonics Natural and Artificial or I prefer to call them pinch harmonics.
Natural Harmonics can be produced by touching your index finger on your fret-hand above at the 5th, 7th or 12th fret. Just place your finger on the string above the fret, don’t press to hard or you will mute the note, pluck the note and then pull your finger off. Try it on the A string.
Timing is critical when playing harmonics. The length of time you keep your finger on the string will determine if you hear a harmonic, muted sound or just a regular note. Natural harmonics occur in various locations along the fretboard. The most common ones are on the 5th, 7th, and 12th fret. The harmonics in those positions will ring for all 6 strings on the same fret. Try playing them in all 3 positions. Place your finger across all 6 strings and play from the Low E to the high E lifting your finger as your pick strikes each individual string. You have to work at this and it takes any time, but it sound so cool.
Pinch harmonics are done with the pick hand hand. I found this technique very difficult to master. The best method is to “choke” down on your pick so there is very little pick exposed between your thumb and your index finger. With time you’ll learn the pick has to be mobile in your hand, and you will move it into different position depending on how you play. Now when you pluck a string with your pick the trick is to hit the pick first and then slightly twist your thumb so that it touches the string immediately after hitting the string.
Why play a pinch harmonic…. . well because they are very cool when playing solos. You can combine string bends with pinch harmonics and vibrato to get totally cool sounding “squeals”. They even sound great when you do them by accident. The trick is to devote any of your practice time everyday to just playing cool licks and try adding a pinch harmonic with any demonic vibrato. Oh yea, it makes you need to play more guitar because you can just create any of coolest sounds!