Only country to have a musical instrument (the harp) as its national emblem

IRELAND

This European nation is known as the "Emerald Isle" and its official symbol appears on its presidential seal and euro coins.

This clue points to Ireland because it’s the only country in the world that features a musical instrument—the harp—as its official national emblem. The harp has deep cultural roots in Ireland, appearing on coins, government documents, and even the logo of Guinness. No wordplay here—just a straightforward fact about national symbols.