This harp calls down the fury of the storm and grants it to all listeners.
Enhancement Bonus: attack rolls and damage rolls
Bards can use this item as an implement for bard powers and bard paragon path powers. As an implement, it grants a +6 enhancement bonus to attack rolls and damage rolls, and it deals 6d6 extra damage on a critical hit.
Power Daily (Standard Action)
Use this power during a short rest. At the end of the short rest, you and each ally who remained within 20 squares of you during the rest are affected by this power. Until the end of each affected character's next short rest or extended rest, his or her attacks deal 5 extra lightning damage.
Published in Player's Handbook 2, page(s) 211.