Arabic. ("pronouncement ", "invocation" or "rememberance ") also spelled zikr based on its pronunciation in Turkish and Farsi.

Dhikr is the remembrance of God commanded in the Qur'an for all Muslims. To engage in dhikr is to have awareness of God. Dhikr as a devotional act includes the repetition of divine names, supplications and aphorisms from hadith literature, and sections of the Qur'an. More generally, any activity in which the Muslim maintains awareness of God is considered dhikr.

The Sufi orders engage in ritualized dhikr ceremonies. Each order or lineage within an order has one or more forms for group dhikr, the liturgy of which may include recitation , singing, instrumental music , dance, costumes, incense, meditation, ecstasy, and trance. (Touma 1996, p.162). Dhikr in a group is most often done on Thursday and/or Sunday nights as part of the institutional practice of the orders.

A group dhikr ceremony in Arabic countries is usually called the hadrah ("presence", referring not to God's presence but to that of the spirit of the Prophet Muhammad and to the awareness of each participant). The hadrah marks the climax of the Sufi's gathering regardless of any teaching or formal structure. Musically this structure includes several secular Arab genres and can last for hours. (ibid, p.165)

The hadrah section consists of the ostinato-like repetition of the name of God over which the soloist performs a richly ornamented song. Often the climax is reached through cries of "Allah! Allah!" or "hu hu" ("He! He!"), with the participants bending forward while exhaling and stand straight while inhaling. The articulation of the name of God progresses as follows, with upward beams indicating inhalation and downward beams indicating exhalation:

The hadrah is directed by a shaykh of the tariqa or one of his representatives; monitoring the intensity, depth and duration of the phases of the hadrah, the shaykh aims to draw the circle into deep awareness of God. Dhikr ceremonies may have a ritually determined length or may last as long as the shaykh deems his murids require.

Source

• Habib Hassan Touma (1996). The Music fo the Arabs, trans. Laurie Schwartz. Portland, Oregon: Amadeus Press. ISBN 0931340888.