Rock producer Paul O’Neill, who founded the progressive American rock band Trans-Siberian Orchestra, has died. He was 61.

News of O’Neill’s death was confirmed in a statement on Trans-Siberian Orchestra’s Facebook page on Wednesday evening, which explained that his death was due to a chronic illness.

“The entire Trans-Siberian Orchestra family, past and present, is heartbroken to share the devastating news that Paul O’Neill has passed away from chronic illness,” read the statement. “He was our friend and our leader — a truly creative spirit and an altruistic soul. This is a profound and indescribable loss for us all.”

O’Neill began his career in the music industry as the personal assistant to manager David Krebs at Leber-Krebs, a management company that worked with Aerosmith, AC/DC, Def Leppard, and others. O’Neill promoted tours in Japan and co-produced Aerosmith’s two “Classics Live!” volumes in the mid-eighties. Around the same time, he also built a relationship with Savatage, a heavy-metal band from Tarpon Springs, Florida, producing their 1987 LP, “Hall of the Mountain King,” and each of their subsequent releases through 2001’s “Poets and Madmen.” He also produced albums by Badlands, Heaven, and Metal Church.

O’Neill co-wrote “Christmas Eve/Sarajevo 12/24,” which combined the popular Christmas tunes “God Rest Ye Merry Gentlemen” and “Carol of the Bells,” with Jon Oliva, Savatage’s guitarist, for that band’s 1995 album “Dead Winter Dead.” Hoping to expand his vision on that song, he convened the Trans-Siberian Orchestra with Oliva and Savatage guitarist Al Pitrelli as well as keyboardist Robert Kinkel, and the group eventually put out the album “Christmas Eve and Other Stories” and released the song as a single.

Trans-Siberian Orchestra’s Facebook page asked fans to respect O’Neill’s privacy for the time being, and said that additional announcements would be released shortly.