Like all veteran journalists who cover global religion news, Robert Moynihan of "Inside the Vatican" is used to getting interesting emails from sources in interesting places.

Normally, Moynihan asks the questions. But that wasn't the case in 2006 when he heard from Russian composer Hilarion Alfeyev, who was completing a new Passion According to St. Matthew, based on scripture and prayers from the Orthodox Divine Liturgy.

It's crucial to know that, in 2006, this composer was already a Russian Orthodox bishop. Today he is known as Metropolitan Hilarion and, as chair of his church's Department of External Church Relations, he has long been a key player in behind-the-scenes talks seeking a meeting between the pope of Rome and the patriarch of Moscow.

In that email, the composer said his goal was to premiere the work in Moscow in March of 2007 -- just before Easter in a year in which Catholics (using the Gregorian calendar) and the Orthodox (on the older Julian calendar) would celebrate the Paschal feast on the same day.

Hilarion wondered "if there might be a way for this work to then be performed in Rome and if I could help organize such a concert," said Moynihan. "We both knew this would be incredibly challenging. … But we did it and that night was like a miracle."

The Moscow premiere was on March 27 and, two nights later, the exhausted Russian choir and orchestra were in Rome for a performance attended by several Catholic Cardinals, as well as numerous students, scholars and dignitaries. One Orthodox participant was Metropolitan Kirill -- now the Russian patriarch.

Anyone probing the roots of the historic encounter between Patriarch Kirill and Pope Francis -- the first meeting of this kind between Rome and Moscow -- must study the years of cultural and musical contacts that built a bridge to this moment, said Moynihan, in an interview days before the Cuba summit. In the end, mutual concerns about the slaughter of Christians in Iraq and Syria made such a meeting an urgent necessity.

When announcing the summit, Metropolitan Hilarion said the crisis in "the Middle East, in North and Central Africa and in some other regions, in which extremists are perpetrating a real genocide of the Christian population, has required urgent measures and closer cooperation between Christian Churches. In the present tragic situation, it is necessary to put aside internal disagreements and unite efforts for saving Christianity in the regions where it is subjected to the most severe persecution."

In addition to the 2007 St. Matthew's Passion performance -- which aired on the Catholic Eternal Word Television Network -- Moynihan noted other landmark events, including:

* The decision by Pope John Paul II, months before his death, to return to Russia the Icon of the Blessed Mother of Kazan, also known as "the Protection of Russia." The Polish pontiff had long yearned for reconciliation between Catholics and the Orthodox, allowing the church to "breathe with two lungs," East and West.

* A standing-room-only 2007 performance of Hilarion's Christmas Oratorio in the massive Basilica of the Immaculate Conception in Washington, D.C. This was linked to an exhibit -- including an icon of Mary, with bullet holes -- on the history of suffering and then renewal in the 20th century Russian church.

* In 2010, Pope Benedict XVI attended another concert in Rome featuring sacred works composed by Hilarion, who sat with the pope.

* The 2013 "Concert for Peace" in Rome following the call by Pope Francis for a day of prayer for those suffering in Syria and across the Middle East.

These events did not receive waves of news coverage, noted Moynihan, but they were important developments on a deeper level.

"If you are trying to understand the Russian soul, then you have to talk about music and iconography and worship," he said. "That is simply a statement of fact. … There are eternal mysteries that are inexpressible, other than through silence and art. These mysteries are real, whether you want to believe in them or not.

"These contacts between Rome and the Russian church -- there has to be more there than politics and economics. There will have to be contact made at the level of the heart and the soul if anything is going to last."