Harmonics
A harmonic is a chime-like sound that happens when you touch a vibrating string to create an extra node. A node is a point on the string where there is no vibration when the string is played. Normally, there are two nodes on a string – at the saddle and the nut (or fret). But if you place your finger lightly on a string at the halfway point (or any other harmonic division of the string – the 7th fret, 5th fret, or 3rd fret) you create a new node which divides the wavelength in half. This increases the pitch of the note, creating a harmonic. For more on the science of harmonics check out Harmony Central’s great article.
Natural Harmonics
To play a harmonic, place one of your left hand fingers lightly on a string over the twelfth fret. Then pluck the string with your right hand and lift your left hand finger off. This should produce the “chime” that is often heard in Hawaiian music. If it doesn’t, keep trying. The hardest parts of playing natural harmonics are defining the left hand finger’s pressure on the string and timing your pluck and release. It helps to pick closer to the bridge when playing natural harmonics.
Major frets that natural harmonics work at: 12th, 7th/19th, 5th, and sometimes if you’re good, the 3rd.
Notes of natural harmonics by fret: 12th = GCEA, 7th/19th = DGBE, 5th = GCEA, and 3rd = DGBE
Artificial Harmonics
Playing artificial harmonics is a way to make a note sound an octave higher than the original note played. Great examples of artificial harmonics are the intros to Jake Shimabukuro’s “Mrs. Robinson” and “Heartbeat (reprise)”.
Artificial harmonics are played with your fretting hand holding the note that is to be played in harmonics, and the thumb and index finger of your picking hand forming this kind of shape:

The index finger of your picking hand (still in the same shape) touches the string the equivalent of twelve frets higher than the note your left hand is fretting. Use your thumb to pick the same string and lift your right hand away to hear the sound of your beautiful artificial harmonic.
Artificial Harmonics MP3 (Heartbeat Reprise Intro)
Harp Harmonics
Harp harmonics are a cool way to add a little something more to your ‘ukulele playing. The concept is very simple – hold a chord and play some notes normal and some notes with artificial harmonics.
The first note is normal and the second is a harmonic. This alternates all the way down the strings. The picking pattern goes like this: 3 4 2 3 1 2 1. Say you are holding a G chord, the tab would look like this:
A |-----------------2-------2<14>-
E |---------3---------3<15>-------
C |-2---------2<14>---------------
G |---0<12>-----------------------
I find that using my middle finger to pick the non-harmonic notes works best. Then I use my index and thumb to play the chime.




Very usefull! Thanks!!