Raison d'être (french for "reason to be") is the name of a Swedish dark ambient musical project, whose sole member has always been Peter Andersson. (Not to be confused with another identically-named individual making music in a similar vein, under the name Deutsch Nepal.)

The music produced by Raison d'être is chiefly dreamlike dark ambient soundscapes, with industrial and gothic touches. For example, synthesizers might play a droning melody over the sounds of metal on metal. Andersson often mixes Gregorian chants with his own keyboard and percussion playing.

Official website: http://raisondetre.coldmeat.se