This part is still under construction.
Meanwhile, let's quote Fred Crane. We still lack much information on jew's harp in many parts of the world. The IJHS is the right place to address your findings, through our blog, newsletter, and journal.
Trumppeople should ask themselves if they don't want to spend their next vacation in the field. Record as much as possible. Get a good interpreter and quiz players and others for whatever they can say about their pieces, their techniques, and the sociology of the trump. Yes, these are things ideally carried on by trained ethnomusicologists. But in my opinion it is better to plunge in without a life vest, and just do it.
Frederick Crane. 2003. “What is to be done?”. VIM 11: 8.