Shadowtime is the first opera by Brian Ferneyhough, written to an English libretto by Charles Bernstein. It was written from 1999 to 2004 and was premiered on 25 May 2004 at the Prinzregententheater in Munich. The City of Munich commissioned the composition and libretto in 1999 for the Munich Biennale. It is in seven scenes (Bernstein 2008):

1. New Angels/Transient Failure
2. Les Froissements d'ailes de Gabriel
3. Doctrine of Similarity
4. Opus contra naturam: A Shadow Play for Speaking Pianist
5. Pools of Darkness
6. Seven Tableaux Vivants Representing the Angel of History as Melancholia
7. Stelae for Failed Time

The composer regards Opus contra naturam, a scene set to the composer's own text and played by a Liberace-like figure, as the centre-piece of the opera (Whittall 2003, 27).

The opera begins with the suicide/death of philosopher Walter Benjamin and goes on to deal with various aspects of his writings and philosophy from the point of view of his descent into the underworld (Bernstein 2008).

• Bernstein, Charles. 2008. "Shadowtime: An Opera by Brian Ferneyhough" (includes extensive set of links) (Accessed 12 March 2022).
• Whittall, Arnold. 2003. "Connections and Constellations". The Musical Times 144, no. 1883 (Summer): 23–32.

• BBC Radio 3: Opera On 3. "Ferneyhough's Shadowtime, 12 November 2005".
• Fitch, Lois, and John Halls. 2010. "Failed Time, Successful Time, Shadowtime: An Interview with Brian Ferneyhough". In Contemporary Music: Theoretical and Philosophical Perspectives, edited by Irène Deliège and Max Paddison. Aldershot: Ashgate. ISBN 978-0-7546-0497-6.
• Ferneyhough, Brian. 2006. "Content and Connotation, Distance and Proximity: Re-presenting the Auratic in Shadowtime", transcribed by Alwyn Tomas Westbrooke. In Komponieren in der Gegenwart, edited by Jörn Peter Hiekel, 10–17. Darmstädter Diskurse 1. Saarbrücken: Pfau-Verlag. ISBN 978-3-89727-337-5.
• Kramer, Lawrence. 2006. "'Au-delà d'une musique informelle': Nostalgia, Obsolescence, and the Avant-garde". Muzikologija: Časopis Muzikološkog Instituta Srpske Akademije Nauka i Umetnosti 6:43–62.
• Lack, Graham. 2004. "Munich: Ferneyhough's Shadowtime and Other New Operas at the Biennale". Tempo 58, no. 230 (October): 51–55.
• Lippe, Klaus. 2006. "'Who's to Say, What's to Say': Anmerkungen zur Rezeption von Brian Ferneyhoughs Oper Shadowtime—Im Kontext der Kunsttheorie Niklas Luhmanns". Musik & Ästhetik 10, no. 37 (January): 26–40.
• Reininghaus, Frieder. 2008. "Elaborierter Komplexismus: Brian Ferneyhoughs Shadowtime". Musik-Konzepte, no. 140 (April): 89–103.