Nachtmahr is a name of least three artists:
These are videos from concerts where Nachtmahr played, so they may be of other bands that played the concert as well.
Das Ich / Elegant Machinery / Nachtmahr Oct 31, 2013 L'Hospitalet de Llobregat, Catalonia, Spain Added by Sssinistre
XVII. Wave-Gotik-Treffen May 9 - 12, 2008 Leipzig, Saxony, Germany Added by John Collins
