Ani Ma’amin (אני מאמין, “I Believe”) is a niggun (ניגון ) or a Hasidic melody. Its popularity during the Holocaust is attributed to Reb Azriel David Fastag, a Modzitzer Hasid (a Hasidic group originating in Poland), who, the Zemirot Database writes “was divinely inspired to sing it on a train to Treblinka”—a forced labor camp and killing center.
It eventually made its way to the Modzitzer Rebbe, Shaul Yedidya Elazar, who said: “With this niggun, the Jewish people went to the gas chambers. And with this niggun, the Jews will march to greet Moshiach.” It is based on Rambam’s Shloshah Asar Ikkarim, the twelfth of the “Thirteen Fundamental Principles” of the Jewish faith. Ani ma’in b’emunah sh’eimah b’viat hamashiach, v’af al pi sh’yitmameah, im kol zeh achakeh lo b’chol yom sheyavo.
Ani Ma’amin (“I Believe”) by the Miami Boys Choir.
Ani Ma’amin (“I Believe”) by David Dudu Fisher at the March of the Living, in 2015, at the site of Auschwitz-Birkenau
Ani Ma’amin (“I Believe”) with the seventh Lubavitcher Rebbe, Menachem Mendel Schneerson, leading the singing at a Farbrengen on 24 Tammuz 5736 (July 22, 1976).