Kai has developed a very interesting way of playing which he calls ‘One_Hand_Bass’ He actually plucks the string with one hand only. See the video here
But Kai plays also the ‘classical’ tapping way and in the following videos he explains simple harmonic techniques.
Here are four video lessons on simple harmonic practice on the scale of C Major.
In the first Video Kai explains a simple IIm7 V7 IM7 classical progression, namely, in the key of C Major: chords Dm7 G7 CM7. The notes of Dm7 are (D F A C), the notes of G7 (G B D F ) and of CM7 (C E G B). First of all Kai does not use all the notes of the chord, for instance in Dm7 we might use only (D F C), the third and the seventh being always the most important. So the progression becomes Dm7=(D F C) G7=(G B F) CM7=(C E B) Next, there is the possibility to make a rotation of those chords to join them smoothly. For instance in order to join Dm7=( D F C) you might use the rotation of G7=( D B F) keeping the D on both chords. So the progression becomes Dm7=(D F C) G7=(D B F) CM7=(C B E)
In lesson 2, Kai continues to explore the same progression, but adding some notes in order to build, 4 or 5 notes chords.
In lesson 3, Kai comes with a bass line , notice that he plays this line using his special One-Hand-Bass with a plucking fingering. The bass line is always on the same chord progression: On Dm7 he plays bass notes A F D C , on G7 he plays B, D F A, and he finishes with G on C7. So we could rewrite this as Dm7 / (A F D C ) G7 / ( B, D F A) CM7 / (G). Then Kai tries some other voicings on the melody chords.
In lesson 4, Kai develops a more melodic bass line Dm7/ (A C E) G7 /(B E, G, B D ) CM7 / (A). The melodic interest is created by using notes with different functions on the first place of each chord: starting with A, the fifth of Dm7 , then B, the third of G7, ending on A the sixth of CM7
Notes by Daniel Schell