Used in Magian Trial 2709. Need to retrieve 50 Iron plates and reward is a Pyf Harp with +4 String Instrument Skill (on top of the +1) for a total of 5 String Instrument Skill. Leads to two more trials to create an Empyrean Harp with +20 Singing Skill, +20 String Skill + song duration bonus and "Grants an additional song effect".