Besides some very obvious targets like Éowyn, Arwen Undómiel, Círdan the Shipwright and Galadriel with her Mirror of Galadriel this is a really good card to circumvent all those quests and effects that make you discard cards. It works at his best in a Noldor deck, that's for sure, but it can be useful even with Legolas, Protector of Lórien, Steed of Imladris on a non - Noldor hero and so on.
Attach to a hero.
Response: After a card is discarded from your hand, exhaust Silver Harp to return that card to your hand.
The Treachery of Rhudaur #90. Spirit.
Sure, it is good and appears a necessary combo with Arwen Undómiel, Erestor, etc., but... In practical play, I see that I think it costy in quest first rounds - where it surely is at its most potent and necessary - and not so essential in the last rounds with a functionning board state. Am I the only one to feel that way ?