Background: Trans-Siberian Orchestra (TSO) is an American rock band founded around 1993 by producer, composer, and lyricist Paul O'Neill, who brought together Jon Oliva and Al Pitrelli (both members of Savatage) and keyboardist and co-producer Robert Kinkel to form the core of the creative team. The band gained in popularity when they began touring in 1999 after completing their second album, The Christmas Attic, the year previous. In 2007, the Washington Post referred to them as "an arena-rock juggernaut" and described their music as "Pink Floyd meets Yes and The Who at Radio City Music Hall.
Context: Paul O'Neill has managed and produced rock bands including Aerosmith, Humble Pie, AC/DC, Joan Jett, and Scorpions, later producing and co-writing albums by the progressive metal band Savatage, where he began working with Jon Oliva (who had left Savatage to spend time with his family and take care of personal matters), Al Pitrelli and Robert Kinkel. O'Neill took his first steps into rock music in the 1970s when he started the progressive rock band Slowburn, for whom he was the lyricist and co-composer. What was intended to be the band's debut album was recorded at Jimi Hendrix's Electric Lady Studios and engineered by Dave Wittman. Although Wittman's engineering was capturing the exact sound O'Neill was hearing in his head, O'Neill was having trouble with it because many of his melodies were between two and three octaves. Rather than releasing an album that he was not happy with, he shelved the project, but continued working in the industry at Contemporary Communications Corporation (also known as Leber & Krebs), company at the time.  Over the years, O'Neill continued to work as a writer, producer, manager, and concert promoter. In 1996, he accepted Atlantic Records' offer to start his own band. He built the band on a foundation created by the marriage of classical and rock music and the artists he idolized (Emerson, Lake & Palmer, Queen, Yes, The Who, and Pink Floyd, and hard rock bands such as Aerosmith and Led Zeppelin and the multiple lead vocalists of the R&B groups the Temptations and the Four Tops). He brought in Oliva, Kinkel, and Pitrelli to help start the project. O'Neill has stated, "My original concept was six rock operas, a trilogy about Christmas and maybe one or two regular albums."  In the 1980s I was fortunate enough to have visited Russia. If anyone has ever seen Siberia, it is incredibly beautiful but incredibly harsh and unforgiving as well. The one thing that everyone who lives there has in common that runs across it in relative safety is the Trans-Siberian Railway. Life, too, can be incredibly beautiful but also incredibly harsh and unforgiving, and the one thing that we all have in common that runs across it in relative safety is music. It was a little bit overly philosophical, but it sounded different, and I like the initials, TSO.
Question: When was the Trans-Siberian Orchestra formed?

Answer:
Over the years, O'Neill continued to work as a writer, producer, manager, and concert promoter. In 1996, he accepted Atlantic Records' offer to start his own band.