Like many other Hassidic movements, Chabad-Lubavitch has its own unique niggunim, or traditional melodies. Chabad niggunim were either composed or taught by the Rebbe of Chabad or their Hassidim. Niggunim are used to aid for meditation during Chasidic prayer or Torah study, as well as during farbrengens. some of these ancient Chabad melodies have recently made their way into mainstream music. Source: Wikipedia (en)