The psalter is an old stringed instrument.This stringed instrument is already mentioned in the Bible.
In old churches there are often figures of the family of David holding a triangular stringed instrument on their lap.
Originally it was played like a harp.
There is also a string for every note of the scale.
It was only recently, around 150 years ago, that the practice of playing this instrument with a bow.
Due to the triangular shape, there is space between the string hangers on each leg to be able to bow each individual string.
So on one side of the instrument the strings are tuned according to the scale, on the other side the semitones.
This makes the bowed psaltery playable chromatically.
You can pluck the strings like a harp or bow.
The bowed steel strings have a spherical sound.
The open strings that resonate create a strong resonance.
The sopran-psalterium has 1 1/2 Octaves from Do (C) to sol (G), ca. 50 cm long.
The alto psaltery has 2 Octaves from sol (G) to sol (G), ca. 57 cm lang.
It starts a little lower than the soprano string psaltery but also ends on the high sol (G). The lower strings also make the resonance of the instrument deeper and richer.
The tenor-psalterium has 2 1/2 Octaves from Do (C) to sol (G), ca. 68 cm lang.
The deepest note is one octave deeper than the deepest note at the soprano psaltery