Used as a place of worship for centuries, first by Christians and then by Muslims (from 1453), the Hagia Sophia (Istanbul) still amazes people from all over the world. Since 1934, it is a museum – but more than that, the Hagia Sophia, a unique architectural work of monumental proportions in Christian Antiquity and the Middle Ages, is described as a mystical place. Monumental, yet mysterious, a 'miracle of space', a symbol, a sign. 'Sophia', the holy wisdom, accompanies us through the whole Bible history. The line and sound of Hagia Sophia are based on a symmetrical eight-note row (mode B) with the notes B, C sharp, D, E/F, G, A flat (G sharp), B flat (A sharp). Although the major-minor relations are removed, harmonic connections (colours) emerge nevertheless.