What is the Old Musician's mission in the novel, Music of the Ghosts?

In the novel's conclusion, the Old Musician reveals that Suteera’s father (also a musician) had asked him to find his instruments. Though Suteera’s father was a musician, he was forced by the Organization to become an instrument maker. He had attempted to bury his instruments but failed to do so in time. The Old Musician makes this his mission - to go back to Sokhon’s village and find them, which he does.