Guzheng music is written in jianpu — numbered notation — rather than on staves. Jianpu has seven numbers; the guzheng uses five of them. That is why the first thing to learn is which two numbers are not on the strings.
The seven numbers. 1 2 3 4 5 6 7 are do re mi fa sol la si. The larger the number, the higher the note, and from 1 up to 1 with a dot above it is one octave.
The guzheng uses 1 2 3 5 6. A standard guzheng is tuned to a pentatonic scale — gong, shang, jue, zhi, yu — with no 4 (fa) and no 7 (si) in the octave. The 21 strings are therefore the group 1 2 3 5 6 repeated upwards four times, plus one top 1.
How the 21 strings are laid out. Counting from the string farthest from you — the thickest and lowest — towards your body: strings 1–5 are 1 2 3 5 6 in the low octave, 6–10 the next octave, 11–15 above that, 16–20 above that, and string 21 is the top 1. Within each group the higher string number is the higher note.
Green strings are 5. Strings 4, 9, 14 and 19 — the sol of each group — are wound in green nylon so you can find your place among 21 strings. Find a green string first and count outwards; it is far quicker than counting up from string one.
Dots above and below. A dot above the number means an octave higher, a dot below means an octave lower, and two dots mean two octaves. A 1 with a dot above belongs around string 16, not down in the bass.
Where 4 and 7 come from. They are not in the tuning, so the left hand presses them out: press string 3 (mi) up a semitone and you have 4; press string 6 (la) up a semitone and you have 7. Press too far and it goes sharp, too little and it stays flat — which is exactly why left-hand pitch is the hardest part of the early stages.
Rhythm lives under the numbers. One line under a number makes it an eighth note, two lines a sixteenth; a dot to the right is a dotted note, adding half its value; a dash between numbers sustains the note; vertical lines are bar lines. The time signature sits at the top, and guzheng pieces are usually in 2/4 or 4/4.
Five fingering marks to start with. tuo (pluck outward), mo (pluck inward), gou (middle finger inward), cuo (two fingers together) and yao (rapid alternation). Symbols vary slightly between method books, so follow the one you are learning from; these five are enough for simple pieces.
How to practise from jianpu. Three steps: sing the line first, getting pitch and rhythm right before touching the instrument; then play slowly, slowly enough that you cannot make a mistake; then add a metronome, starting at 60. Skipping the singing is the most common bad habit there is.
Tune before you read, because a badly tuned instrument teaches your ear the wrong pitch (see tuning, from ear to electronic tuner). String numbering and replacement intervals are in guzheng strings, and what each exam grade tests is in the grading system. If you are unsure what to work on at your stage, tell us where you are.