Melodies from the Beis HaMikdash

Rav Yitzchok Isaac taught that the tunes he heard, even those that came from Hungarian folk songs, were really from the Beis HaMikdash. They had been lost among the nations over the years, and he had found them and returned them to the Jewish people. As proof, he said that the non-Jew who taught him a song would forget it as soon as the Rebbe had learned it.