Get ready for changes to your Sunday Mass. 

When Father Jeff Keyes arrived at St. Edward's Parish in the summer of 2004, he found a thriving, multiethnic parish of 5,400 families on the eastern side of the San Francisco Bay. Keyes' religious order, the Missionaries of the Precious Blood, had sent him to become pastor of one of the order's two remaining parishes in California.

While pleased with many aspects of his new assignment, there were certain things that bothered him. Passionate about the liturgy, Keyes felt that the parish's approach to the celebration of the Eucharist conveyed a somewhat casual attitude toward this central mystery of the Christian faith.

It was an accumulation of small things, notes Keyes, who recalls, for example, that the parish was using a loose-leaf lectionary rather than a bound copy. Keyes was troubled by the idea of having a "throwaway Word of God," as he puts it.

A trained musician with a number of published compositions to his credit, Keyes was particularly disturbed by the parish's musical repertoire. At his first Mass, for example, the choir sang "Gather Us In," whose third verse begins, "Not in the dark of buildings confining, not in some heaven light years away." Keyes was frustrated that a Catholic hymn would appear to dismiss our desire for heaven. "I said to people at the parish, ‘That's not what we believe!' " says Keyes.

In the months after he became pastor, Keyes set about making changes. Many were small, such as the decision to purchase real candles for Advent rather than the plastic oil lamp candles that had been used previously. "The point of an Advent wreath is to mark the passage of time," says Keyes. "You need real candles to do that." Keyes also found craftsmen within the parish who refurbished the ambo, baptismal font, and tabernacle.

It was Keyes' decision to radically reshape the parish's music program, however, that generated the most controversy. Keyes essentially banned the use of a number of popular contemporary hymns, particularly "praise and worship" songs with lyrics that sometimes reflect a Protestant theology. "They are not appropriate for a Catholic Mass," says Keyes.

His most striking innovation was to transform the parish's 10 a.m. service into a "sung Mass," with many parts being sung in Latin using Gregorian chant. Keyes favors using the chants from the Graduale Romanum and the Graduale Simplex-the two official chant books for the Mass-even though few parishes make use of them because of the complexity of the music.

The first few months were difficult. The original choir of almost 30 voices dwindled to a small handful. A number of families left the parish. Some parishioners accused him of wanting to return to a pre-Vatican II liturgy. The charge is ironic, says Keyes, because the Second Vatican Council's Sancrosanctum Concilium (Constitution on the Sacred Liturgy) specifically envisioned Catholics learning to sing the key parts of the Mass in Latin.

Not everyone was displeased with the new direction, however. After his first Christmas Mass at St. Edward's, one older parishioner came up and said, "Thank you for giving us our church back." A woman who now drives 20 miles to attend the 10 a.m. Mass every Sunday wrote Keyes a three-page letter thanking him for providing a "dignified, prayerful, and truly artistic celebration" of the Mass.

A visitor to St. Edward's 10 a.m. Mass finds an intriguing mix of old and new. Much of the "ordinary" of the Mass-the parts that recur from week to week, including the Kyrie, Gloria, Sanctus, and Agnus Dei-is chanted in Latin, as are the "propers," that is, the antiphons that are used for a particular Mass at the entrance, offertory, and Communion processions. The readings and homily and most (but not all) of the congregational responses are in English, as is the Eucharistic Prayer, which Keyes chants from beginning to end. Although Keyes has worked to teach parishioners the basics of chant, the congregation still tends to drop out on some of the more complex pieces.

Donalyn Deeds has been a parishioner at St. Edward's for more than 30 years and currently serves as the parish's director of religious education. She considers Keyes a friend as well as a boss and has not hesitated to challenge him on some of his changes. "I think we moved too abruptly," she says. "This parish had been doing contemporary music for such a long time. It's what people were used to."

Deeds concedes, though, that Keyes may have brought a much-needed sense of reverence back into the liturgy. "There is a lack of formality that is pervasive throughout our entire culture. People show up for Mass late and they leave early. They come in T-shirts and jeans. I think Father Jeff may have brought some needed discipline."

Although some of his parishioners see him as a conservative, Keyes resists the label. "When I preach about immigration, people think I'm a liberal. When I seek to do what the church asks when we celebrate the liturgy, people think I'm a conservative. All I seek to be is Roman Catholic," he says.