Notation System
Here, the traditional Satsuma-Biwa notation system is introduced. The system uses a tablature notation in which we can recognize elements like the four horizontal staff lines, the note heads (either a white or black triangle or a circle) and note head numbers.
Four horizontal staff lines

The four lines represent the original four strings of the Biwa. However, on the now-a-days five string Biwa, the top string is doubled. Traditionally the 4th and 5th strings are plucked together. For this reason, throughout this Biwa Vocab the 4th and 5th strings will be simply referred to as 'the 4th string'.
Triangle note heads

Down stroke, called 'Chan'.

Up stroke, called 'Gi' or 'Gin'.

This sample shows an up and down stroke with left finger placed on the string: 'Chan' and 'Gi'. The white triangle (in contrast to black triangles) indicates to use just one finger.

The number above the triangle note head is the number of Chû (fret). In this sample, the number indication '3' indicates that the left-hand finger should be placed above Chû 3 (more precisely: between Chû no. 2 and 3).
The point under the triangle indicates the amount of pressure which should be applied:
3-without-point: left hand finger at Chû 3 pressing softly
3-with-one-point: left hand finger at Chû 3 pulling the string inward properly
3-with-two-points: left hand finger at Chû 3 pulling the string inward strongly

The sample shows again an up and down stroke: 'Chan' and 'Gin'. However now two or three left hand fingers are placed on the strings. The black triangle indicates to use several fingers, which can be useful to increase the pressure.

The Chû 5 has a special indication concerning pressure. Here are no additional points used to express the amount of pressure, but additional numbers:
• 5 above the triangle: left hand fingers at Chû 5 pressing softly
• 6 above the triangle: left hand fingers at Chû 5 pulling the string inward properly
• 7 above the triangle: left hand fingers at Chû 5 pulling the string inward strongly
Circle note heads

The circle note head indicates an up respectively down stroke on an open string.
Sustained Sound

The line connected to the triangle note head indicates the movement of the sustaining sound,
Tremelo

Plucking one or more strings in both directions: down-up-down (so-called 'Sha-Gi-Shan'). This is performed by drawing a kind of 8 over the strings. This technique is called 'Hachi-no-ji' (which literally means 'letter 8').

Tremolo on one or more strings