German electronic music act Enigma became huge in the pop-music world more than 25 years ago, when they hit on an unlikely but winning formula - merging Gregorian chants with airy dance beats.
The song Sadeness (Part I), from their 1990 debut album MCMXC a.D., topped the charts in 24 countries, including Britain, Germany and Japan.
Together with their later albums, Enigma has sold 70 million records worldwide.
Now, composer-producer Michael Cretu, the main man behind Enigma, has finally released the sequel to the tune - Sadeness (Part II).
In a telephone interview from his studio in Munich, the 59-year-old says: "If Sadeness (Part I) was like a question, after 26 years, the new song is like the answer."
The song is the lead single from Enigma's recently released eighth album, The Fall Of A Rebel Angel, following 2008's Seven Lives Many Faces.
Cretu says the long break between the seventh and eighth albums was because he wanted to take time off from the Enigma project and "do something different".
As he worked on other music projects, such as a musical version of the 1927 German sci-fi classic film Metropolis, he found himself gaining "new ideas" as well as "renewed energy" to work on new Enigma material.
On the inspiration for the album, he says: "It's been 26 years since the beginning of Enigma and I thought, as a way to celebrate a quarter of a century, that the new album should remember the spirit of the first album.
"So it has concepts such as mystical situations, the conflict between religion and sexuality and the importance and symbolism of numbers."
He worked with close friend and collaborator Michael Kunze, a Grammy- and Echo-award-winning German theatre veteran, for the album's storyline and lyrics, which he describes as the "story of a symbolic journey to redemption".
The album comes in several editions and the most extensive version, dubbed the Super Deluxe Edition, includes narration in English, Spanish and French.
He also engaged German painter Wolfgang Beltracchi to come up with paintings for each of the album's 12 songs.
While the themes may be similar to those of Enigma's first album, Cretu made sure that the music in the new album is modern and contemporary.
He engaged Indonesian singer Anggun, best known for her 1997 global pop hit Snow On The Sahara, to sing three songs, including Sadeness (Part II).
He says: "Anggun is one of my favourite singers. I love her voice and she can speak English and French, she's perfect.
"I was impressed with the way she worked, she did a brilliant job and the result is exactly as I wanted it."
Born in Bucharest, he studied music in the Romanian city and later in Paris and Frankfurt.
He worked with prominent German music figures in the 1970s and 1980s, including producer-songwriter Frank Farian, pop group Hubert Kah, as well as other European acts such as British progressive-ambient music veteran Mike Oldfield.
He has also released music under his own name.
Of the global success his music has enjoyed, he says he is "extremely happy and proud".
"My intention is always to make music that everybody can understand, no matter their religion, skin colour or where they live."