He-Man and the Masters of the Universe (1983)

Season 1: Episode 8

Adam, Teela, Orko, Cringer and Lizard Man are on a visit to Pangus, the King of the city of Tarinth, when the city comes under a fierce trembling. Adam is about to come to the rescue as He-Man when a young woman called Celice appears and soothes the tremors with her singing. Pangus explains that a terrible creature lives beneath the city, and only Celice's soothing singing can calm it. Skeletor oversees the whole scene and decides that Celice's singing powers would be of great use to him. Evil-Lyn kidnaps the girl with Trap Jaw, and possesses her; Skeletor plans to use her siren song to hypnotise The Sorceress and then to sing Castle Grayskull's jaw-bridge open...