Al-Ghazzali discussed the use of music and dancing in "dhikr" and the mystical states it induces in worshippers, as well as regulating the etiquette attached to these ceremonies, in his short treatise on Islamic spirituality "The Alchemy of Happiness" and in his highly influential work "The Revival of the Religious Sciences". Al-Ghazzali emphasized how the practices of music and dance are beneficial to religious seekers, as long as their hearts are pure before engaging in these practices. Notable examples include the Mevlevi Order founded by Jalaluddin Rumi, which was the main Sunni order of the Ottoman empire, and its "sama" ritual (known in the West as "the whirling dervishes"). The Mevlevi order, its rituals and Ottoman classical music has been banned in Turkey through much of the 20th century as part of the country's drive towards secular "modernisation", and the order's properties have been expropriated and the country's mosques put out of its control, which has radically diminished its influence in modern Turkey. In 2008, UNESCO confirmed the "Mevlevi Sama Ceremony" of Turkey as one of the Masterpieces of the Oral and Intangible Heritage of Humanity, and the practice is now regaining interest. In Egypt and the Levant, the Mevlevi form of "sama" is known as tannoura and has been adopted (with some modifications) by other Sufi orders as well. The Chishti order, traditionally the dominant Islamic institution in Afghanistan and the Indian subcontinent and the most ancient of the major Sufi orders, also practices forms of "sama" similar to the Mevlevis, as well as other forms of devotional dance such as "dhamaal". The order is strongly associated with the development of Hindustani classical music and semi-classical devotional genres such as "qawwali" through famed pioneer figures such as Amir Khusrow. The Chishti order remains one of the largest and strongest Muslim religious orders in the world by far, retaining a vast influence on the spirituality and culture of around 500 million Muslims living in the Indian subcontinent. Other examples of devotional dance are found in the Maghreb where it is associated with gnawa music, as well as Sub-Saharan Africa and South-East Asia. The Naqshbandi order, predominant among Iran's Sunni minority, is a notable exception in that they do not use music and dancing in the context of "dhikr".