During the Nineties, a small miracle occurred in the world of music: Some thirty monks, doing just what they did every morning, merging song and praise in a context of meditation and prayer, caught the attention of the public and became the number one bestseller in America. They were the monks of Santo Domingo de Silos, the famous Benedictine monastery in the Spanish province of Burgos. Now, just over a decade after this amazing boom that drew attention to a centuries-old tradition, Gregorian chant continues to fascinate the devout and the secular alike. This religious music, which is sung without accompaniment, can be heard live in its natural setting: a handful of monasteries across Spain continue to resound with the echoes of their medieval past. Many of them offer guest accommodation - male, female or mixed - for those seeking the mysticism or tranquility of the monastery. Here we offer the best places to experience first-hand this musical prayer in Latin that consists, in the words of St Paul, of "singing to God in your heart."