Dragonbone lyre

A dragonbone lyre was used to subdue the guardian of the Shadow Swamp in the Plane of Shadow in the early 1370s DR.

Description
This lyre was small and fine and seemingly carved from the bones of a dragon. A piece of parchment tied to it gave some musical notes and read "Play this, and the guardian at Black Tree Bend will subside—Esvele." It was worth 800 gold pieces. It had a haunting sound.

Power
Although not magical, a specific tune played on the dragonbone lyre would cause the guardian—a massive zombie dragon turtle—to subside back into the depths of the swamp and let travellers pass.

History
In the early 1370s DR, the priestess of Shar Esvele Graycastle supplied the dragonbone lyre and its tune to the shadar-kai ferrymaster Sithierel so he could sail the Necreme on the Whispermere untroubled by the guardian she'd placed there. It may have been found by adventurers in service to Mystra when they came through in early Eleint of the Year of Lightning Storms, 1374 DR.