The first thing you hear is the plinking of bone against bone in quick rhythmic trills. The first thing you see is a curious-looking siren virtually wrapped from her long neck to her lengthy curling tail in informal vestments of seaweed and sponge. Whereas most merfolk you've seen—especially the females—have voluminous tresses of sea-green hair, this one is entirely bald, revealing prominent cranial fins. The plinking is coming from a marimba of sorts, crafted from the ribcage of what must have been a massive fish.
The plinking stops as the siren becomes aware of your presence. She quickly sets down a pair of fishbone mallets, tugging at her coverings to be sure no part of her below the neck or above the wrists is exposed. She turns (really just rolling over to lean on her other flank) to see who has arrived.
"How many have you brought?" she drawls in a high, shrill voice. She extends one webbed hand, clutching her clothes tighter to her body with the other. "The lamps! Give them to me—I must have all of them!" And only now do you notice: in the corner of the grotto sits a massive pile of discarded lamps of every variety—old and new, metal and clay, pristine and shattered beyond repair.
