By MARY M. BYRNE

The King's Singers, the prolific U.K.-based vocal ensemble, built its worldwide reputation since 1968 with an eclectic repertoire spanning Renaissance music to pop and folk.

But the group's newest offering, "Sacred Bridges," collaboration with the Germany- based vocal and instrumental group Sarband, makes a different kind of statement.

Using voices, instrumentation and dance, the two groups perform Psalms the bible's famed songs of praise and sorrow set to music by 17th- century Muslim, Christian and Jewish composers. And because the Psalms are held sacred by all three religions, the project is, organizers say, a dramatic illustration of the historic connections among them.

It's not unusual for the King's Singers to team up with other artists - they have worked with Paul McCartney, Bruce Johnston of the Beach Boys and orchestras worldwide - but their collaboration with Sarband presented something new.

As musicians work in within the Christian musical tradition, says David Hurley of the King's Singers, "we have notes in front of us. We follow the scores."

But the musicians in Sarband - who work with Middle Eastern traditions, weaving together Islamic, Jewish, Christian and South Asian threads - often improvise. Because they are continually responding to subtle cues from each other, their performance changes from night to night and moment to moment.

The members of Sarband are, Hurley says, "powerful collaborators." Led by Romanian- born composer Vladimir Ivanoff, the group of mostly Turkish musicians plays music that is by turns sparse, haunting and gently rhythmic.

And along with the musicians, Sarband brings two whirling dervishes who, in the tradition of Islamic mysticism, perform prayerful, spiraling dances along with the music.

"As they flow around with their robes flying, they generate quite a breeze around them." Hurley says. "It's the most extraordinary thing. It's almost like a meditation in dance because there is this movement, and yet it is so calm."

But even though the repertoires of Sarband and King's Singers may appear distinct and alien to each other, Hurley says, they are historically connected.

Jewish, Muslim and Christian musical traditions from the Middle East to Western Europe have borrowed from and influenced each other for thousands of years, and the Psalms of David are a case in point. In the 17th century, composers took and interpreted the same texts in song, each according to their own musical traditions.

And the King's Singers have long performed the works of Salamone Rossi, a 17th-century composer and convert to Judaism who wrote striking style music in six-part harmony - but in Hebrew, and intended for Jewish worship.

"Sarbandis basically doing what they do, brilliantly, and we do what we are happy doing and yet the two have this wonderful historical and textual link," Huriey says.

Sarband and the King's Singers recorded together in May in St. Andrews Church; in Toddington, England. Much of the album was recorded in the round, so to speak, with the two groups facing each other as they played.

"There was a wonderful sense of performing to them and they were performing to us," Hurley says.