Ictus is a Brussels-based contemporary music ensemble. Founded by Belgium's Flemish Community, and formed while "on the road" with the Flemish choreographer Wim Vandekeybus, the ensemble's home since 1994 has been the ROSAS dance company's premises. Headed by Anne Teresa De Keersmaeker, the dance troupe has often been accompanied by Ictus. Their actual collaborative venture is set to involve one of Gérard Grisey's masterpieces, Vortex Temporum.

Ictus is a permanent group of 20 or so co-opted musicians. A sound engineer is a regular presence in their midst, as are the various instrumentalists – a sign of the massive movement ensembles are seen to be making towards the status of a mixed "electric orchestra". The issue of formats and listening systems has now been put in the mix: mini or maxi concerts, mystery programmes (the Blind Dates in Ghent), concerts with comments, concerts-cum-festivals where the audience is at liberty to roam around the stages (the landmark Liquid Room events showcased in Brussels, Vienna, Ghent, Darmstadt, Hamburg or Luxembourg).

Ictus joins forces with Bozar (Palais des Beaux-Arts) and the Kaaitheater every year. The line-up of performances is an opportunity to experiment with new programmes to be offered to a non-specialist audience with broad cultural interests. The ensemble has also been in residence at the Lille Opera House (e.g. in 2004 Avis de Tempête by Georges Aperghis or in 2011La Métamorphose by Michaël Levinas).

Ictus has also formed a partnership with the Ghent School of Arts to launch an Advanced Master's degree course, focused on interpreting contemporary music. Another string to the ensemble's bow is the collection of recordings it has built up, mainly published by the Cyprès label. Recent releases are MichaëlLevinas opera La Métamorphosebased on Franz Kafka’s narration (2012), Luciano Berios Laborintus II, along with Mike Patton (2012) or Jonathan Harvey’s Wagner Dream (2012).

Ictus has performed in most of the major concert halls and leading festivals (Musica Strasbourg, Brooklyn Academy of Music, the Autumn Festival in Paris, ArsMusica, Royaumont, Milano Musica, Wien Modern).

Since 1996 Georges-Elie Octors is the conductor of the Ictus Ensemble. Octors studied at the Royal Academy of Brussels and conducted world creations such as Kaija Saariaho, Georges Aperghis, Jonathan Harvey, Michael Jarrell, Fausto Romitelli, Luca Francesconi, Henri Pousseur, Philippe Boesmans and Toshio Hosokawa. Nowadays he's in charge of the 'Formation aux Langages Contemporains' at the Conservatory of Liège and Chamber Music at the Escuela Superior de Musica de Catalunya (Barcelona).