score:3
The distinction between perfume and a musical instrument is that the perfume is consumable and the instrument is not. When you leave the EU and claim your refund, the customs official inspecting your goods wonβt be checking whether the instrument is used, because it isnβt consumable. From this more complete guidance
no certification of export will be given for used consumable items, for example, perfume which is wholly or partly consumed in the EU
As Michael Hampton rightly points out, the instrument must be bought from a shop which participate in a VAT refund scheme. However, I donβt think it will be too much trouble to find such a shop. With a quick google search, I found several.