I tried to recreate it but could not. What is this trick called? He seems to be semi-touching the strings to make this strange cool string sound.
What is the name of this trick?
How exactly is it done?
0:22 in the video
These are called Guitar Harmonics.
Different areas on the strings of a guitar (and bass guitar) have overtones. Its the same places on each string too, including Halfway from the nut to the bridge, and the halfway points between the Nut and Halfway point, then the Halfway point and the Bridge. There are more points on there as well.
These sounds are made by lightly touching these "Harmonic Hotspots" with your finger, plucking the note (the closer you play to the bridge, the more loud and clear the note will be). Once you play the note, immediately release your finger and it will release.
The points on a guitar with these overtones are called Natural Harmonics when played. There are also false harmonics, where the player fingers a note and creates new custom harmonics, so to speak. Here's more on that because I'm having trouble explaining it further...
I don't know if there is any specific name, but he is simply playing a natural harmonic on the 12th fret and then shaking the neck of the guitar to create a vibrato-like sound.
It is pretty common and widely used. You can do it by simply playing any note and then moving the neck of the guitar up and down quickly (up meaning away from your body whereas down means towards your body).
You can also move the neck only up or down if you just want to change the pitch.
If you don't know how to play natural harmonics, simply touch the string. Don't press it against the fretboard, and play the string.
You can also see this video:
Several harmonics can be played on guitar. The natural ones are found at the nodes at the half, third, quarter, fifth etc. points along the strings, where, when gently touched at that spot when the string is played, will produce a harmonic instead of the fundamental note.
Next come the false harmonics, which work in the same way, but from a fretted note. Press a string on 2nd fret, and touch on 14th, there's the first false harmonic.
Then there's the pinched harmonics, which happen when the r.h. thumb touches a string at its node, just as the string is plucked. As ever, touch at the node.
There are also hammered (tapped) harmonics, which work by hammering a string , again on the node point, pretty quickly. The harmonic will sound, but if you do a mini pull-off as well, you can get the fundamental and the harmonic to sound simultaneously.
There's more but that covers what the guy does, plus.The node points are where a string does not vibrate while the harmonic is sounding. Prove this by touching the string again, while it's sounding - on the node, and the string will continue , a bit further along, the string stops.As stated in another answer, natural harmonics are easier to sound by plucking close to the bridge.