A nigun (Hebrew: ניגון meaning "tune" or "melody", pl. nigunim) or niggun (pl. niggunim) is a form of Jewish religious song or tune sung by groups. It is vocal music, often with repetitive sounds such as "bim-bim-bam" or "ai-ai-ai!" instead of formal lyrics. Sometimes, Bible verses or quotes from other classical Jewish texts are sung repetitively to form a nigun. Some nigunim are sung as prayers of lament, while others may be joyous or victorious.
Nigunim are largely improvisations, though they can be based on thematic passages and are stylized in form, reflecting the teachings and charisma of the spiritual leadership of the congregation or its religious movement. Nigunim are especially central to worship in Hasidic Judaism, which evolved its own structured, soulful forms to reflect the mystical joy of intense prayer (devekut).
A revival of interest in Jewish music was sparked as part of Hasidism. Different Hasidic groups have their own nigunim, often composed by their Rebbe or leader. Hasidim gather around holidays to sing in groups. There are also nigunim for individual meditation, called devekus or devekut (connecting with God) nigunim. These are usually much slower than around-the-table nigunim, and are almost always sung without lyrics. The Baal Shem Tov, founder of Hasidism, spoke of devekus nigunim as "songs that transcend syllables and sound." Several tunes attributed to him are still used today.
Some nigunim originate from non-Jewish sources. Hasidic Jews, based on a practice of their founder Rabbi Israel Baal Shem Tov, have adapted anthems and even folk songs, ascribing them a new spiritual dimension. For example, Chabad Hasidim have adopted the French tunes of La Marseillaise and Napoleon's March, as well as Russian or German drinking songs as a part of their liturgy. Many Hasidim believe that these songs, in their secular forms, are in spiritual exile. By adapting them to liturgical forms, they are "raising Holy Sparks" according to the teachings of Rabbi Isaac Luria's system of kabbalah. (The same justification is used for the use of Arab tunes for Sephardic pizmonim.) The process continues to this day, with new nigunim emerging from time to time.