Their music is characterized by using a classical mixture of female and male voices, Gregorian chants, bagpipes and other unconventional elements.
During a trip to the US, Neo met some Argentinians and was inspired to rename the group "Penumbra" (Spanish for "Twilight").
Between 1999 and 2000, Penumbra performed in concert in various parts of France, such as Bordeaux and Lyon, as well as internationally in Switzerland and at the Leipzig (Germany) festival.
The second album, The Last Bewitchment, was released three years later in 2002 after an extensive line-up change in 2001, on the Season of Mist label.
It is their first album without longtime keyboardist Xavier "Zoltan" Robin and their first with female vocalist Valérie Chantraine.