In 1999 Le mot de passe (Eng: The password) was produced by Pascal Obispo, on which Kaas was accompanied by an orchestra on several tracks. Jean-Jacques Goldman again contributed to the making of the studio album, among others with 2 songs Une fille de 'l'Est (Eng: A girl from the East) in which Kaas praised her East French heritage and Les chansons commencent. The French singer Zazie wrote the track J'attends de nous. The song Les éternelles (Eng: The eternals) was also published in Germany as a duet with the Swiss tenor Erkan Aki under the title of Unter der Haut (Eng: Under the skin), and was the theme music of the five-part ZDF serial Sturmzeit (Eng: Stormy Times), based on a book by Charlotte Link.
In June 1999 Kaas appeared at the benefit concert Michael Jackson & Friends in Seoul, South Korea and Munich. Apart from Kaas and Jackson, Mariah Carey, Luther Vandross and Status Quo also put in appearances. The special events, in aid of UNESCO, the Red Cross and the Nelson Mandela Children's Fund, were broadcast to 39 countries.
In September 1999, Kaas came third in Marianne, a poll for the national symbol of France, behind supermodels Laetitia Casta (first) and Estelle Hallyday (second). Most pictures of Kaas from her last albums (from Dans ma chair to Sexe fort in 2003) show the singer in very figure-accentuating clothes and suitably daring poses, and her music videos are seldom restrained performances.