By Alexander Gelfand

In the grand, world-historical scheme of things, the Renaissance represented a huge leap forward for European Christendom. For Muslims and Jews — well, not so much.

Islamic scholars furnished the classical texts that provided the underpinning for much Renaissance thought. Yet by the 15th century, the Islamic world itself had begun the long, slow, backward slide from which it has yet to recover. And Renaissance humanism didn't quite extend to the Jews, who were confined to ghettos in those countries that didn't expel them altogether.

It's ironic, then, that the English vocal group the King's Singers should have sought to connect the three great world religions by collaborating with the Middle Eastern ensemble Sarband on a program of Renaissance-era psalm settings by Jewish, Christian and Muslim composers. But the material on their new CD,"Sacred Bridges," did indeed result from a series of cross-cultural exchanges — some prosaic, others downright bizarre.

That Dutch organist and composer Jan Pieterszoon Sweelinck or French Huguenot composer Claude Goudimel chose to set a number of psalms in the rich, polyphonic vocal style of their era should come as no surprise. Nor should it raise eyebrows that Jewish violinist and composer Salamone Rossi Hebreo, who served in the court of Vincenzo Gonzaga, duke of Mantua, did the same. Yet the circumstances of Rossi's life were hardly ordinary. In 1612, Gonzaga established a Mantuan ghetto modeled after the one in Venice. A Jewish notable in a city where Jews were second-class citizens, Rossi was exempt from having to wear the yellow "badge of shame" that was the Jewish uniform of the day. While it is often pointed out that Rossi avoided writing music for the church, and revolutionized synagogue music by introducing the use of vocal polyphony (Jewish sacred music had, until Rossi's intervention, been primarily monophonic and modal, like Gregorian chant), he did so by turning synagogue music into church music; his psalm settings are practically indistinguishable from the sacred Christian music of his era. The only things even remotely Jewish about Rossi's synagogue motets are the Hebrew texts themselves. (Hearing the King's Singers pronounce biblical Hebrew in their toff English accents is like listening to Prince Charles say Kaddish.)

The real mind-bender among the composers represented on "Sacred Bridges," though, is Ali Ufki (né Wojciech Bobowski), a Polish church musician who was enslaved by Crimean Tartars and sold to the court of the 17th-century Ottoman sultan, Mehmed IV. Clearly a man who knew how to make the best of a bad situation, Ufki converted to Islam and absorbed the modal music of his Ottoman hosts as completely as Rossi had mastered the polyphonic style of his Christian counterparts. Not only did Ufki translate into Turkish the texts of the psalms he worked with, but he also took melodies from the early Calvinist hymnbook known as the Genevan Psalter and "modalized" them in the Turkish manner. (An early master at what modern sociologists call "identity switching," Ufki also wrote a Latin treatise explaining Islam.)

While the King's Singers give voice to the intricate, multipart music of Sweelinck, Goudimel and Rossi, Sarband — which was founded by the Bulgarian musicologist Vladimir Ivanoff, and includes such Middle Eastern instruments as the qanun (a plucked zither), the ney (an end-blown flute), the kemanche (a spiked fiddle) and the bendir (a frame drum) — puts the flesh back on the bones of Ufki's compositions. Sometimes the two groups alternate track by track; sometimes they combine forces on the same piece, and sometimes they switch back and forth between different settings of the same psalm, as they do with Ufki's and Goudimel's radically different treatments of Psalms 5 and 9. The contrast between the two ensembles and the traditions they represent couldn't be greater, or more illuminating.

Early European music and early Middle Eastern music had more in common than one might expect. Both gave primacy to vocal melody, both treated sacred music as a vital means of spiritual expression, and both allowed plenty of room for improvisation. In terms of timbre and texture alone, the combination of ney, qanun, kemanche and bendir could almost pass for a Renaissance ensemble of recorder, cittern, viol and tambourine.

Nonetheless, as "Sacred Bridges" makes clear, these two kinds of music work in very different ways. Listening to the interplay between the multiple melodic lines voiced by the King's Singers, one almost can see the individual parts in one of Sweelinck's or Rossi's compositions gliding past one another like smooth slabs of sound, and sense the mathematical relationships between countertenor, tenor, baritone and bass. This is coolly cerebral music whose attraction lies in its structural complexity. Sarband's heterophonic interpretations of Ufki's psalm settings, in which Turkish singer Mustafa Dogan Dikmen incants his verses in a nasal, glottal-stop-filled style and each instrumentalist plays a slightly different version of the same melody to hypnotic rhythmic accompaniment, sounds like something from another world entirely — which, of course, it is.

Ironically, the essentially irreconcilable nature of the two styles underscores the bridge metaphor of the album's title. These musics can't really be fused, but they can be made to stand side by side, giving us the chance to appreciate the unique charms of both — despite the considerable distance that separates them.

Alexander Gelfand is a writer living in New York