Sister Marie Keyrouz (also spelled "Kairouz") was born in Deir-El-Amar in Lebanon. Raised in the Maronite Church, she took holy orders in the Melchite (Byzantine Rite Catholic) Church. From an early age Keyrouz simultaneously undertook several disciplines of study, earning a joint doctorate in musicology and anthropology from the Sorbonne in Paris in 1991. Keyrouz engaged in a lifelong quest for a variety of so-called "Oriental" Christian chants, mostly preserved in Greek and Arabic manuscript sources and through oral tradition. She brings to this area of study detailed knowledge of Western chant and easily sees a commonality of approach that scholars on either side of the liturgical (and political) fence seem to have heretofore missed. As a result, her debut album Chant byzantin pretty much took the West by surprise upon its arrival in 1989, not only with the apparently ancient repertoire it represents, but also due to Keyrouz' own incredible virtuosity; her ability to sing the tiniest intervals in rapid flourishes, notes that are difficult for most singers to hear, let alone reproduce. Since then Keyrouz has produced a number of albums, all best-sellers, that illustrate various aspects of her many-sided interests: Maronite chant, Melchite chant, Milanese chant, and even mainstream Gregorian chant and settings based on it. In some cases she is accompanied by L'Ensemble de la Paix, a small band of Arabic instrumentalists that she leads. Keyrouz is founder of L'Instituit International de Chant Sacré (International Institute of Holy Songs) in Paris, which promotes research into ancient sacred song on a worldwide basis and raises money to help impoverished Lebanese schoolchildren. One controversial aspect of Keyrouz's work is the lack of obvious historic documentation accompanying her recordings. Keyrouz is thoroughly familiar with the statistical regimen attendant to such projects as she undertakes, and many scholars are aware that very old sources of Eastern chant tend to be of the "text only" kind. Keyrouz remains somewhat vague about the sources of her melodies, stating that they are "traditional" within a certain practice of singing or liturgy. While this is bothersome to some of her colleagues, it will not concern most others, as Keyrouz' voice is a fabulous instrument that has a universal appeal. For further clarification of her goals and ideals, Keyrouz has outlined them in two books, Je chante Dieu and Chant Cultuel Dans la Vie de L'Homme.