The Song of Amalek is about a boy named Shaul who during the Purim in Mezhibuzh was asked by the Baal Shem Tov to sing for the audience.
Baal Shem Tov just finished his teaching of Amalek in which he warned his followers that Amalek still lives. Baal Shem Tov taught the gathering that whenever doubt or despair enters their heart, then that is Amalek trying to destroy your relation and faith in God. They must fight back and destroy Amalek so that you can serve God completely and with joy.
He then called for Shaul, who was a little boy to show how he best served God. Shaul sang the Shoshanat Yaakov which celebrates Gods salvation and joy. Shaul sang in such a beautiful voice that afterwards he was invited by Baal Shem Tov to study the Torah with him.
After the Shabbat, Baal Shem Tov, along with two other students, offered to personally escort Shaul to his home town. On the way they came across an inn full of noisy, singing drunk patrons. While being accompanied and asked by the Baal Shem Tov sang the Shoshanat Yaakov in front of the crowd of drunks at the wayside inn. Among those at the inn who heard Shaul sing were three little boys around the same age as Shaul.
Years later Shaul would once again encounter those three little boys. By this time Shaul was a young businessman rushing to get home to his family to join them in celebration but was waylaid by 3 bandits who were going to kill him and take his money. Knowing that he was going to die soon he begged the bandits to allow him to let him say the Vidui prayer, or final confession, so that he could return his soul to his Maker in peace. With his imminent death fast approaching, Shaul decided to sing the Shoshanat Yaakov one more time. Once again he sang with the same joy and happiness he recalled when he sang for Baal Shem Tov and the multitude of followers when he was a little boy.
After singing the three bandits were awed into silence and surprise. They had heard that song before. Shaul also at that moment realized that he had met the three bandits before. They were the three young boys at the inn way back when he sang for them at the request of Baal Shem Tov. After realizing who Shaul was the three bandits asked for forgiveness and returned the money. They also agreed to turn away from banditry and live honest lives.