IF ELEVENTH century artists are to be believed, the sacred melodies of the Gregorian chant were whispered into the ear of Pope Gregory I (540-604) by the Heavenly Dove itself. Alternatively, a 1950 Roman Catholic edition of chants for the church year assures us that it has come "from the holy Fathers, some of whom learnt this way of singing from the Angels." Most scholars today believe the repertory is based on melodic ideas that predate Christianity--possibly derived from the music of the Jewish temple, possibly stretching through Jewish usage back into remote antiquity.

Remoteness and antiquity can pose problems. About 20 years ago the Roman Church virtually eliminated both the Latin language and the chant. Both were considered too remote from the people. Ironically, there is now more public interest in the chant and what it represents than ever before. A recent National Public Radio broadcast on the chant elicited a deluge of inquiries from listeners. Roman Catholic monasteries that had abandoned it are bringing it back, often with English words. And at Catholic University this week, more than 500 Catholics from all over the world are gathering for workshops and performances related to the chant.

The underlying melodic formulas of the chant may once have been considered magical, and indeed some believe they still are. There is something remarkable about the persistence of the chant throughout the Christian era, as well as the fervor it has inspired. Western classical music would be unthinkable without it; indeed the Western system of pitch notation was devised in order to record and preserve it.

What is this extraordinary repertory of liturgical melody? It is the traditional music for the Catholic Mass, and for the eight prayer services sung each day in Roman and Anglican monasteries. As a rule, every prayer hour of every day of the year has its unique chant, so the repertory includes several thousand melodies.

But facts and numbers say little about the music itself. As it is most often interpreted today, the rhythm of Gregorian chant is entirely different from that of any other music familiar to us. There is no "beat," no "drive." Perhaps more than any other, this quality of being rhythmically suspended in time gives the chant an otherworldly feel. By universal agreement among those who sing it for religious reasons, the chant is the great prayer language of the church. It is palpable stillness. It is a quieter of the mind, which allows a deeper listening to awaken in the inner self, the self that listens to the living silence of the universe. Like all liturgy, all prayer, its purpose is to create a state of openness and vulnerability in the worshipper.

The chant's impression of timelessness is paradoxical. If you sing it regularly, you begin to suspect that this extraordinary music doesn't transcend time but contains it. In the chants for Lauds, there is almost the taste of the morning itself; in the last chants of Compline, you can almost touch the darkness. During the vespers for Christmas Eve, the quality of expectation in the time becomes nearly tangible.

In this way the chant not only facilitates prayer, but also gives a kind of substance to profound but elusive spiritual realities. But for those who are just passing through the church, the casual benefits are also considerable. As National Public Radio put it, a tense and harried listener at a service of chant will begin to calm, until "little by little a feeling of well-being comes over him."

I once stood in the nave of Chartres Cathedral and was struck by the way the light from the windows seemed to catch the world in a perpetual sunrise, which then mixed with the perpetual deep midnight of the shadows from the stones, all juxtaposed on the vast empty space above me and the extreme age of the entire enclosure. I had never been confronted with anything even remotely similar in the United States, except in the singing of the chant services.