How is the character of the erlking differentiated musically in the song?

In Schubert's "Erlkönig," the character of the Erlking is differentiated musically through his lyrical, flowing melodies that contrast sharply with the agitated piano accompaniment representing the father and the child. The Erlking's music is more serene and seductive, often in a higher register, which highlights his enchanting and deceptive nature. Additionally, the dynamics and tempo shift when the Erlking speaks, creating a sense of urgency and drawing the listener into his beguiling presence. This stark contrast captures the tension between the dangers of the Erlking and the desperation of the father and child.