You didn’t say what country you are sending the instrument to, or for what reason. Most countries make the assumption that you are sending the instrument there to sell it, and they want to make sure they will get their money(import duty, VAT tax, et.). So they will charge you accordingly up front. Telling them it’s only temporary or you’re planning to take it back out of the country means nothing to them. You will have to pay all fees as if you are selling the instrument there. So you need to research this carefully BEFORE sending the instrument off. You may have to buy a bond, which is basically a contract with a bond company that tells the country in Europe that all fees will be paid by the bond company if you don’t take the instrument back out of the country. At the very least you will probably have to pay about 25% of the value of the instrument for the import duty and VAT tax that will be due immediately.
I should add one more thing here. If you have a choice between buying a bond or paying all the fees up front, even if you are planning to remove the harp from the country after a certain amount of time, buy the bond. In the long run it’s cheaper. Also, the consulate of the country you are going to will tell you that upon removing the harp from their country you will have to fill out paperwork to get a refund, they make it as difficult as possible to get the money back. So the best is to not pay it out in the first place.