In celebration of its 50th anniversary and in advance of the public reopening of the Notre-Dame Cathedral in France, the Gregorian Choir of Paris is launching its inaugural U.S. tour this weekend — an 11-day trip that will include three free concerts in Maryland.

The tour, “A Tribute to Notre Dame de Paris,” by the 30-member choir aims to highlight the enduring significance of the art form, and to thank Americans who contributed more than $13 million in less than a year to rebuild the Cathedral following the devastating 2019 fire.

The French Heritage Society reported receiving $2.45 million from American donors in 2019, while the Friends of Notre Dame de Paris contributed $10.6 million that year, according to the organizations’ websites.

“We wanted to visit your country because we appreciate very much the help of people from the U.S.,” choir member Pierre Loiret said.

“Notre-Dame is the heart of the French people. When the Cathedral burned down, it was a real disaster for us. So when the Cathedral reopens, it will be as though our heart is beating again.”

Just like the scaffolding that protected Notre Dame as it was being rebuilt, the music performed Friday in Annapolis, Saturday in Baltimore, and Thursday in Bethesda — Gregorian plainsong chant — is the basis for nearly all forms of contemporary choral music, from hymns at Sunday services to holiday caroling parties.

The western tradition of polyphony or the combination of two or more musical lines? You can thank Gregorian chant for that, according to Classical Music magazine.

Modern staff notation? It’s based on Gregorian neumes, an early form of musical notation.

Vladimir Stoupel, the Baltimore-based pianist and conductor who helped arrange the group’s debut U.S. tour, compared a Gregorian chant to a spider’s intricate architectural constructions.

“Gregorian chant is like a web of voices,” Stoupel said. “It’s a conversation between several people in which each voice enriches the previous voice. Sometimes one voice leads, and sometimes another one does. It’s very concentrated and rich and dense.”

The chants, which weren’t intended to be purely music or purely prayer but a seemingly magical mixture of both, flourished in the Middle Ages.

“Whenever you sing or chant, your prayer goes higher,” said Philippe Etienne, former U.S. ambassador to France, and a supporter of the choir.

“You express your faith, your trust and your love from deep inside your being as a believer. It is a powerful instrument to support your conversation with God.”

But the oral art form nearly died out in the 19th century, according to the choir’s website. It was saved from obscurity through a series of painstaking musical transcriptions by scholars at a French abbey.

The Gregorian Choir of Paris was founded in 1974 in an effort to rediscover and popularize the art form. The choir’s founders were university students when they began receiving training in Gregorian musicality and spirituality from French monks.

“Gregorian chants are not intended to be performed as a concert,” Loiret said. “It is sacred music and cannot be separated from the liturgy.”

And yet, the chants received a powerful boost in the late 20th century from a decidedly secular source, according to Classical Music magazine. The German band Enigma included excerpts of Gregorian chant in their 1990 hit single “Sadeness (Part I).”

That single, and the 1994 album “Chant,” which had been recorded two decades before by Benedictine monks, was credited for a resurgence in Gregorian chant’s popularity among teens and young adults who were drawn to the long melodic lines and the sense of mystery.

“If you don’t know your past,” Stoupel said, “you will never know your future.”

While the tour aims to introduce new audiences to the beauty of the chants, choir members also hope to recruit students to study the art form.

Students from St. John’s College in Annapolis, from The Baltimore Academy high school and from Columbia University in New York will be invited to apply for a two-year scholarship to study Gregorian chant and choral directing in Paris, Etienne said.

The organization will select two students to receive scholarships. When they graduate, the students will be awarded a diploma and will be equipped to begin directing their own choirs.

But Etienne said you don’t have to believe in God to appreciate the art form.

“The popularity of Gregorian chant is bigger today than it was in the past,” he said. “You don’t have to be a Christian to love this music.”

mmccauley@baltsun.com