Renowned Dutch violinist and maestro André Rieu, the founder of the waltz-playing Johann Strauss Orchestra, featured Greek soprano Christina Petrou performing the best-known Greek Christmas carol, Christos Genate (Χριστός γεννᾶται), during a live performance in Maastricht last week.

The specific melody, entitled “Christ is Born”, is a mainstay of the traditional kalanta (caroling), sung the day before Christmas, often by children going door-to-door accompanied by a triangle. Other carols are sung the day before New Year’s and on the Epiphany, Jan. 6.

The specific carol heralds Christ’s birth and its joyous, devotional lyrics that call for praise and celebration.

In his introduction, Rieu explained the tradition behind the carols, describing how children go from door to door on Christmas Even singing and receiving sweets in return. He compared the custom to Halloween in the United States and to Germany’s St. Martin’s Day.

“Fortunately, I have a Greek singer in my chorus who really loves sweets,” Rieu joked to the audience, adding: “It’s a lovely, simple song. If you hear it often enough, you’ll be able to sing along with us—and you might even earn a few treats.”