Canticles of Harmony
Exploring Petrichor
1 - After triggering the first cutscene, head into Petrichor and approach the NPC shown as ??? in the town square.
2 - Then follow the quest navigation to the seal into the Faded Castle. Defeat the Praetorian Golem that is guarding the Score and pick it up from the Pedestal to unlock the seal, then enter the Faded Castle.