The great German poet and philosopher Johann Wolfgang von Goethe once remarked that the best architecture could be described as "silent music." This relationship between architecture and music is most visible when looking at the great cathedrals. As host Melinda Whiting points out, during the first nine hundred years of this millennium, cathedrals were the defining image of the cities built around them. Actually, the music you heard within the cathedral was as much a defining part of the community as the building's architectural magnificence, spaciousness and spiritual significance. In this edition of Milestones of the Millennium, we visit some of the world's great cathedrals and examine music written both to celebrate and to take advantage of their grandeur.

Sometimes the mere sight of a majestic cathedral is enough to inspire a musician. Legend has it that the magnificence of the Cologne Cathedral inspired Robert Schumann to compose a symphony, whereby he responded with his "Rhenish" Symphony. Earlier in the millennium, structural aspects of a cathedral were sometimes reflected literally in a musical work. Such is the case with the music of Perotin, a 12th-century composer working at the Cathedral of Notre Dame in Paris. Bob Eisenstein of the Folger Consort remarks that in Perotin's Sederunt principes, the lowest voice moves in slow, deliberate tones, suggesting the firm foundation of the edifice, while the upper three voices soar in gracious arches, suggesting the interior's huge, vaulted ceilings. Perhaps the most sublime aspect of the music is the way the individual voices respond back and forth. The relationship between these moving voices results in a dazzling effect, much like the perception of sunlight streaming through an intricate stained-glass window, which in itself suggests of the light of divine illumination.

The interior space of a cathedral possesses unique acoustical properties. Douglas Major, organist and choirmaster at National Cathedral in Washington, DC, remarks that the stone walls of a cathedral naturally produce a long decay and reverberation, resulting in a "great megaphone" that enables as many as three thousand people to hear a single voice clearly. St. Mark's Cathedral in Venice, Italy, has special physical characteristics that composers cleverly exploited. Giovanni Gabrieli placed singers in the Cathedral's two opposing choir lofts and achieved a natural "stereo" effect. Aural reinforcement by way of the Cathedral's two pipe organs and diverse brass instruments produced a ground-trembling and spiritually awakening sound.

Much music has been written to honor cathedrals. One famous example concerns the Florentine cathedral Santa Maria del Fiore, whose consecration in 1436 was certainly a cause for celebration. The Cathedral was 140 years in the making; the final step alone, the seemingly impossible task of designing a huge cupola that would rest atop the cathedral, took seventy years to complete. This final structural problem was solved by Filippo Brunelleschi, who ingeniously called for the construction of two domes, one inside the other. For the dedication of such an important building, the organizers of the event called upon Guillaume Dufay, the most celebrated composer of the day. Dufay's composition in honor of the Cathedral, the motet Nuper rosarum flores, not only praises the Cathedral with words, but reveres the Cathedral through musical structures. The two lowest voices of the motet sing, in canon, the opening of the chant "Terribilis est locutus est" ("Mighty is this place"). These two interlocking voices seem to suggest the Cathedral's two domes. Furthermore, the motet's sectional proportions, 6:4:2:3, mimic the structural proportions of the Cathedral.

Cathedrals have been inextricably linked to music for the entire millennium, and have inspired musicians to attain the height of their art. As Senior Commentator Martin Goldsmith says, "The magic of Dufay was a sample of the artistic and intellectual achievements of the early Renaissance." Inside a cathedral's sturdy stone walls awaits an other-wordly experience of peace and consolation, but also a place of solemn power that nurtures the soul.

Listen as PT host Melinda Whiting, Martin Goldsmith and organist Douglas Major explore the world's great cathedrals and the sounds they have shaped. Another online feature from Milestones of the Millenium. (This audio segment requires the free RealPlayer 5.0 or higher. You can also listen with a 14.4 connection)