Metastaseis (Greek: Μεταστάσεις; spelled Metastasis in correct French transliteration, or in some early writings by the composer Métastassis) is an orchestral work for 61 musicians by Iannis Xenakis. His first major work, it was written in 1953-54 after his studies with Olivier Messiaen and is 8 minutes in length. The work was premiered at the 1955 Donaueschingen Festival with Hans Rosbaud conducting. This work was originally a part of a Xenakis' trilogy titled Anastenaria (together with Procession aux eaux claires and Sacrifice), but was detached by Xenakis for separate performance.

Date of composition 1954 (1953-1954)
Premiered 1955 in Donaueschingen, Germany
First published Boosey & Hawkes
Approx. duration 8 minutes
Instruments 61x Musical Instrument - Instrumentalists ;
Autotranslations beta Iannis Xenakis: Metastaseis
Iannis Xenakis: Metastaseis
Iannis Xenakis: Metastaseis