Death's Door

After gaining access to the Stranded Sailor on your way up the mountain to fight the big beasty everyone keeps talking about you'll find barb the bard standing next to a wall you must destroy with your bomb spell, and talking to him will reveal he's heading up the mountain to write his best song yet. You will run into him multiple times as you progress through the story, but to unlock this achievement you must return to him at The Stranded Sailor after defeating the mountain baddy and listen to his "Mangum Opus." Of note, he will sleep during the night so ensure your world is set to day for this.