So many types of dance have merged into the dance we know as "Belly Dance" that it is indeed, a fusion style dance ~ always evolving and growing into a more interesting (and often) more difficult form. These are all reasons why, I believe belly dance is now a World Class Dance Art. That means it is considered by educated people to be a leading dance art.
In the world of dance, belly dance has gone from a folk style to a classic style - meaning it is complex and difficult to learn. This, in large is due to the fusion of other dance styles, such as ballet, Indian dance, flamenco and North African dances, not the least of which are the two trance dances that give it that exotic edge.
The most common trance dance incorporated into belly dance is the Zar. It is an exorcism ritual intended to placate demon spirits causing a woman illness or distress. In one version, drummers are hired to play various rhythms while the women dance in a circle. When the correct rhythm is found for the woman, she will pass out and be taken away. Zar is part of North African and Middle Eastern cultures and has become a featured dance in many belly dance shows as an exotic and spooky folk tradition. The rhythm is in 2/4 and when translated into the cabaret, it includes head bobs, rolls and sways. This video is a great overview of The Zar.
The second (and less know or used) trance dance is The Guedra (gee-drah) from Morocco. This dance is a group activity in that one woman after the other joins is and trances until she passes out and then the next woman jumps in the trances until she passes out. The Guedra is a dance of blessings and good will - often performed at weddings. I saw it performed by the Blue People at the 1999 Marrakesh Folk Festival - an awesome event! Belly Dancers also use this dance in belly dance shows also as a spooky addition to the program. Zar is mostly a 6/8 and involves singing and clapping and lots of hand and finger gestures.
Our group just performed one at a Moroccan dinner show. The dancer, Justine did a fabulous job!
The Marraksesh Folk Festival is now in July and is a must for any serious Middle Eastern dancer- you won't be disappointed!