The subject of the opera and the novel is a small town that believes it will soon be under attack from a tribe of nomads. Fear of this rumored attack leads to confessions, obtained through torture, from prisoners of war.
Glass said in an interview earlier this year that the opera, his 21st, is a critique of the current war in Iraq and the Bush administration. The opera's American premiere will take place in Texas, the president's home state, at Austin Lyric Opera, in January 2007.
According to the BBC News, the audience at the premiere gave Glass a 15-minute standing ovation.
Performances of Waiting for the Barbarians in Erfurt run through October 26.