By Ariana Bacle
April 06, 2017 at 12:03 PM EDT
Credit: Paul Bergen/Redferns

Trans-Siberian Orchestra founder Paul O’Neill has died from a chronic illness, the band announced on their official Facebook page Wednesday. He was 61.

“He was our friend and our leader — a truly creative spirit and an altruistic soul,” they wrote. “This is a profound and indescribable loss for us all.”

O’Neill got his start co-producing Aerosmith’s two Classics live albums in the late ’80s and went on to form a relationship with metal band Savatage. He later recruited members from that group, Jon Oliva and Al Pitrelli, to help form Trans-Siberian Orchestra in 1996. That year, they released Christmas Eve and Other Stories, a holiday-themed rock record and the first in their Christmas trilogy, which included the seminal classic “Christmas Eve/Sarajevo 12/24.”

Speaking with Christianity Today in 2003, O’Neill explained the origins of that hit:

We heard about this cello player born in Sarajevo many years ago who left when he was fairly young to go on to become a well-respected musician, playing with various symphonies throughout Europe. Many decades later, he returned to Sarajevo as an elderly man—at the height of the Bosnian War, only to find his city in complete ruins.

I think what most broke this man’s heart was that the destruction was not done by some outside invader or natural disaster—it was done by his own people. At that time, Serbs were shelling Sarajevo every night. Rather than head for the bomb shelters like his family and neighbors, this man went to the town square, climbed onto a pile of rubble that had once been the fountain, took out his cello, and played Mozart and Beethoven as the city was bombed.

He came every night and began playing Christmas carols from that same spot. It was just such a powerful image—a white-haired man silhouetted against the cannon fire, playing timeless melodies to both sides of the conflict amid the rubble and devastation of the city he loves. Some time later, a reporter traced him down to ask why he did this insanely stupid thing. The old man said that it was his way of proving that despite all evidence to the contrary, the spirit of humanity was still alive in that place.

The song basically wrapped itself around him. We used some of the oldest Christmas melodies we could find, like “God Rest Ye Merry Gentlemen” and “Carol of the Bells” (which is from the Ukraine, near that region). The orchestra represents one side, the rock band the other, and the single cello represents that single individual, that spark of hope.

Of the band itself, O’Neill said in a statement on the group’s website, “The whole idea was to create a progressive rock band that would push the boundaries of the genre further than any group before. Way, way further.”

Trans-Siberian Orchestra’s most recent album was 2015’s Letters from the Labyrinth, which peaked at No. 7 on the Billboard 200.