Four Musicians (David?)

Four musicians with their string instruments are placed in the corners of the capital.
A harpist sits in the north-west corner. He seems to be tuning his instrument, for he stretches his left hand down to the pegs, while his right hand is placed over the strings. Both the other figures play on their instruments. One of them holds a bow; another plays on a psaltery, which he has laid over his knees.
The poor conservation of the capital permits no clear interpretation. But since one of the musicians is wearing a crown, he could be a representation of King David.

musician instrument harp Psalter book crown king david