Who kept time with the little drummer boy when he played his drum for Jesus?

In the Christmas song "The Little Drummer Boy," the little drummer boy plays his drum for Jesus, and he is accompanied by the sounds of the other animals present, such as the ox and the lamb, who keep time with him. The song emphasizes the humble offering of the boy's music, which is meant to honor the newborn Jesus. The collective rhythm created by the animals adds to the warmth and simplicity of the scene.