It's not really possible to summarize in a few words the nature of these ceremonies, which take place after dark and are known as lila (the Moroccan Arabic word for 'night'). Books on the subject tend to rely specifically on one or a handful of informants, and therefore provide local or specific accounts of the phenomenon without being able to cover its whole range of regional differences. It's therefore difficult, and perhaps unwise, to give a generalized abstract account of gnawa. Some statements should be uncontroversial, however. The ceremonies involve healing or therapy of individuals regarded as possessed by powerful invisible entities. These entities, referred to as mluk, are a part of Islamic tradition (although their status therein is ambiguous) and are assimilated with related concepts of djinns and saints. As in tarantella and other musical healing practices, the musicians are able (within the proper ritual framework) to work on the relationship between the possessed individual and the entity possessing him or her. The ceremony takes place under the joint guidance of a male master musician (m'allem) and a female 'medium' or 'seer' (entitled moqaddema). The musicians play a three-stringed bass lute (hajhouj), metal castanets (qarqaba) and sometimes a drum (tbel or ganga). They also sing. Anthropologists have cited connections between the songs, the mluk they relate to, colours, smells, ritual objects and so on, not to mention various more complex symbolic patterns (see, for example, V. Pâques, "Le Monde des Gnawa", in L'autre et ailleurs, ed. J. Poirier and F. Raveau, Paris: Berger-Levrault, 1976, pp.169-82).
(A hajhouj. Source: instrumentsdumonde.com.)
I don't intend to comment here on the precise nature of these ceremonies (nor am I qualified to do so). Instead I offer a brief note about the culture of which they are a part, namely, the black diaspora in Morocco. The most thorough published account of this relationship can be found in Pierre-Alain Claisse's recent work Les Gnawa marocains de tradition loyaliste (Paris: Harmattan, 2003). Claisse distinguishes between four related historical movements which together are encompassed by the term 'gnawa': the influx of slaves into Morocco in the sixteenth century; black soldiers serving the Moroccan royal family in the seventeenth century; the confraternity of ritual musicians; and a modern movement among marginalized Moroccan youth.
In the sixteenth century the Moroccan empire, under the Saadian sultan Ahmed el Mansour (ruled 1578-1603), expanded southwards in an attempt to profit from the trade links (specifically salt and gold) of the Songhai empire in what is now Mali. Moroccan forces progressed through the Sahara and captured the important desert trading posts of Timbuktu and Gao, dismantling the Songhai empire in the process. They were unable to consolidate their success, however, and remained in control of this distant territory only briefly. One result of this expansion was the importation into Morocco of black slaves. A number of these entered royal service and by the end of the seventeenth century, under the rule of the Alaouite sultan Moulay Ishmail (1672-1727), their descendants had come to occupy the position of bodyguards to the emperor, a sort of 'praetorian guard' with considerable power of intervention in state affairs. According to Si Mohammed, a gnawa master from Casablanca who was an important source for Pierre-Alain Claisse's book, this group should be distinguished from those who were not attached to the royal family, but instead pursued relatively humble careers as artisans. The former were able to an extent to maintain their military role until independence (1956) and finally lost their position following the attempted coup against King Hassan II at Skhirat in 1971. Meanwhile the latter, in the context of increasing urbanization and modernization, began to lose their traditional role of artisans and, Claisse says, started to find employment as bouncers, parking attendants and other such jobs. This group, however, maintained their identity as musicians engaged in rites of healing and possession, in a context which was avowedly Islamic, but nonetheless susceptible to charges of heterodoxy. Gnawa is often identified with Sufism, although Sufis do not necessarily agree with this interpretation. One Sufi adept, who gave me a lift in his freezer van through the Western Sahara in 2005, was scornful of the idea that gnawa was a Sufi movement. Women dancing and men playing instruments was not true Sufism, in his opinion: instead Sufism involved a path, tariqa, of quiet contemplation.
The potentially non-Islamic side of gnawa is underlined by the story, narrated to Claisse by Si Mohammed, of a gnawa master named Ba Dergo:
"Ba Dergo, a Gnawa from the land of the blacks, had scarification on his face; he went into the royal palace with a two-stringed hajhouj. This first hajhouj of the masters of the cult of possession was made from a big tortoise shell, as found in bilad-as-sudan [West Africa]. I know that two types of people in Morocco have scarification: Berbers and Jews. Now, Ba Dergo was a Jew. He was a Jew, a black Jew, because on his face he had, not tattoos, but scratches, incisions! What's so surprising about it? Since the Exodus, the Jews are to be found in every country on earth, including the bilad-as-sudan." (p.30)On the other hand, as another scholar, Abdelhafid Chlyeh, points out, the gnawi would not themselves tolerate any assertion that they do not have complete adherence to Islam (Les Gnaoua du Maroc, Morocco: La Pensée sauvage, 1999, p.15). Overall, the spiritual entities whom they invoke appear to draw on a mixture of traditions from sub-Saharan, mainstream and Moroccan Islam and pre-Islamic Berber beliefs.
(Painting by Louis Endres. Source: P. Thornton, The Voice of Atlas, London 1936, p.94.)
Not all the descendants of black slaves are part of the confraternity of gnawa musicians, and not all gnawa musicians are black, many being of mixed heritage, Arab or Berber. The confraternity itself can be divided along various lines, geographically or in terms of practice, but generally all its adherents recognize as their ancestor Sidi Bilal, an Ethiopian, early convert to Islam, companion and muezzin (caller to prayer) of the Prophet Mohammed.
Since the 1960s, a subsidiary movement of 'gnawi' has gathered momentum, represented largely by disadvantaged youth who attach themselves to the idea of gnawa without necessarily having the expertise that the confraternity of masters have. To some extent, Claisse points out, this new wave, whom he refers to as 'gnawi sauvages', compete with the established masters in their ceremonial practice. They are viewed, however, as parasitical, and as potentially dangerous, in that through their less than complete understanding of the power of their music they can provoke trances which they are unable properly to control. The growth of this movement was to an extent promoted by the interest in 'folklore' shown by the Culture and Tourism ministries: tourists at hotels in Marrakesh and elsewhere are routinely entertained by groups of 'gnawi sauvages', who are not linked to the established confraternity of masters, whose work remains essentially underground, although they do on occasion perform in more public contexts (in which mluk are not invoked).
In the 1980s Morocco, like much of the rest of the world, was turned on to the sound of reggae (typically Bob Marley).
Young gnawa musicians rapidly came to identify themselves with these black singers, descended from Caribbean slaves, whom they perceived, via the media, as their trans-Atlantic homologues. "We represent the reggae movement in Morocco," they are fond of saying.Claisse notes that he attended a 'very serious' ceremony, at the end of which, to his surprise, the musicians, with the agreement of their master, performed a sort of Bob Marley tribute in Marrakeshi gnawa style (pp.60-1). In this sense the music of the black diaspora can be said to have completed a circular journey, setting out in opposite directions from sub-Saharan Africa, and meeting once again in Morocco at the end of the twentieth century. It should be pointed out that there are also recent connections between gnawa and jazz, specifically in the work of the Tangier-based gnawa master Abdullah el Gourd and his recordings and live performances with pianist Randy Weston and saxophonist Archie Shepp.
(Those interested in this subject should also check out the recent article by Chouki el Hamel, 'Constructing a Diasporic Identity: Tracing the Origins of the Gnawa Spiritual Group in Morocco', Journal of African History, 49 (2008), pp.241-60. Since writing this article I have also obtained a copy of the most comprehensive treatment of gnawa in English, Deborah Kapchan's Traveling Spirit Masters, Middletown CT, 2007, which I highly recommend for a more in-depth account. A set of CDs containing an example of a complete performance cycle was released by the scholar Antonio Baldassarre: see the review by Philip Schuyler.)