The Bone Ocarina is an item in Freshly-Picked Tingle's Rosy Rupeeland.
Uses and Location
The Bone Ocarina is obtained shortly after clearing the second dungeon, the Pirate Hideaway in Cape Treasure. It can be used to summon the Pirates while standing on a dock. These docks can be found in Cape Treasure in the First Continent, the Gooey Swamp in the Second Continent, and Mount Desma in the Third Continent.
Tingle can upgrade the Bone Ocarina after helping the Pirates for a second time in the Gooey Swamp. It can then be used to open the ten hidden blue Pirate Treasure Chests once they are found.