Some 20 years ago when reading a biography of Manuel II Palaiologos, Alexander Lingas learned about the Byzantine emperor’s trip to the court of King Henry IV looking for support for besieged Constantinople. The trip was a major diplomatic effort, starting in 1399 and lasting until 1403. Later, Lingas took a seminar at Oxford about Henry IV and Henry V, and his imagination was caught by the idea of the daily services at the English court and the intersection of religions and cultures.

“The English chroniclers mentioned that Manuel had singers with him and that he did daily services, and the emperor’s simplicity and piety made a big impression on the English chroniclers,” Lingas said. “I thought, this is a unique occasion to be able to juxtapose those two groups of people who would have been under the roof of the same palace.”

Now people can hear that juxtaposition on A Byzantine Emperor at King Henry’s Court: Christmas 1400, London, the latest recording release from the Portland, Oregon-based vocal ensemble Cappella Romana, which Lingas founded in 1991 and continues to direct.

Putting out something unique is nothing new for the vocal ensemble, which performs Byzantine chant and Greek and Russian Orthodox sacred choral music alongside Latin Catholic music from Western Europe — broadly, “music of the Roman inheritance,” referring to “old” Rome and “new” Rome (Constantinople). This combination of repertory is practically unique among choral groups.…