No sound or image so captures the spirit of what Samuel Huntington of Harvard calls "The Clash of Civilizations" between Islam and the West as the adhan, the haunting daily call to prayer heard thoughout the Islamic captials of the world. The Daily Galaxy editorial staff views the adhan as the emerging icon of the 21st Century.
Adhan is called out by the muezzin from a minaret of a mosque five times a day summoning Muslims for fard (mandatory) salah (prayers). There is a second call known as iqama that summons the faithful to line up for the beginning of the prayers.
Click on this Google Video link and listen to the call to prayer from Mecca, the birthplace of the Prophet Muhammad.