This section covers the tapping boards divided into two regions. Usually the total number of strings ranges from 10 to 14. The regions are mainly tuned in fourths-fourths, fifths-fourths or fifths-fifths.
188.8.131.52 THE GRAPHIC SPACE OF THE 4-4 INSTRUMENT
The simple idea behind 4-4 tunings is that identical patterns are played identically on both sides (see FIGURE 1-2). The 4-4 tunings can be divided into mirrored or parallel. Suppose that we take a mirrored tuning, then in order to represent the invariant motif C-F-G-c on the bass side, we simply need to take the sign C-F-G-c of the melody side and to mirror it symmetrically. The bass playing is simply the mirroring of the melody playing.
FIGURE 1-2 Symmetry between left and right hand: The melody space, in fourths, is represented on the right; the bass, also in fourths, on the left.
As they are symmetrical, the signs C-F-G-c reflect each other, and so does the playing. The hands and the motives show the same symmetry.