Tarja Turunen recently spoke to Kerrang! magazine about her December 2017 onstage reunion with NIGHTWISH bassist/vocalist Marco Hietala during a "Raskasta Joulua" concert in Hämeenlinna, Finland. Asked if performing with her former bandmate was a nerve-wracking experience, Tarja said: "Naturally, I was nervous. I hadn't seen Marco in 12 years; we hadn't been in touch. So it would be silly to say I wasn't nervous, but more than anything, I was curious about what he was doing. I just wanted to see him. On the day of the show, he came to knock on my [dressing room] door, as he'd been unable to make rehearsals. It was just, like, 'Hey!' with a massive, long hug after 12 years apart. Just a few things were said, like, 'Great to see you,' and, 'See you soon on stage.' Then we sang those songs, the last of which was 'Ave Maria', just the two of us with acoustic guitars. It was very intimate, yet in front of a huge crowd with thousands and thousands of people in front of us. That was a moment neither of us will ever forget. We were very emotional; the whole place exploded with emotion. It was beautiful."

Pressed about whether her collaboraton with Marco means that there is potential for her to rejoin NIGHTWISH for one song or one tour, or maybe even an album, Tarja said: "I know a lot of fans would love to see something happen, but it's a very long distance away… Personally, I don't see anything happening with me and them, to be perfectly honest. Marco came a little later into the band; he wasn't there since the beginning. He was always a guy I was close to. Me and [NIGHTWISH keyboardist/leader] Tuomas Holopainen, however, haven't seen each other in a long time… but we have been in touch. It's not bad. The past is what it is; we can't change that. We can only change the future."

Turunen was fired from NIGHTWISH at the end of the band's 2005 tour by being presented with an open letter which was published on the NIGHTWISH web site at the same time. In the letter, the other members of NIGHTWISH wrote: "To you, unfortunately, business, money, and things that have nothing to do with emotions have become much more important."

Holopainen later called the decision to part ways with Turunen "the most difficult thing I ever had to do." For her part, Tarja said the way she was kicked out of the group proved that her former bandmates were not her friends. "Maybe one day I'll forgive, but I will never forget," she said.

Dutch singer Floor Jansen made her live debut as the frontwoman of NIGHTWISH in October 2012 at Showbox Sodo in Seattle, Washington following the abrupt departure of the band's lead singer of five years, Anette Olzon.