Michael Andreas Gielen (20 July 1927 – 8 March 2019) was an Austrian conductor and composer known for promoting contemporary music in opera and concert.

Principally active in Europe, his performances are characterized by precision and vivacity, aiding his ability to interpret the complex contemporary music he specialized in.

He conducted notable world premieres such as György Ligeti's Requièm, Karlheinz Stockhausen's Carré, and Bernd Alois Zimmermann's opera Die Soldaten and his Requiem für einen jungen Dichter.

She was an actress who had given up acting when their first child Carola was born, but appeared occasionally, for example as a speaker in the premiere of Arnold Schoenberg's Pierrot lunaire in Dresden in 1919, rehearsed with her brother Eduard Steuermann.

Josef Gielen successfully staged at the Teatro Colón in Buenos Aires, Argentina, in 1938 and 1939, and managed to get immigration papers for his wife and the two children.

[1] As a répétiteur at the Teatro Colón at age 20, he played the basso continuo to the recitatives, in the style of the time, in a performance of Bach's St Matthew Passion conducted by Wilhelm Furtwängler.

[5] He took to freelance conducting in 1965, including the premiere of Bernd Alois Zimmermann's opera Die Soldaten in Cologne that year,[1] a work that had been deemed to be impossible to perform.

[9] During his time in Frankfurt, later called the Gielen Era,[6] he collaborated with stage directors such as Hans Neuenfels for Verdi's Aida and Ruth Berghaus for Wagner's Der Ring des Nibelungen.

[5] He demonstrated a mastery of the most complex contemporary scores, and conducted many premieres, including Helmut Lachenmann's Fassade and Klangschatten – mein Saitenspiel, György Ligeti's Requiem, and Karlheinz Stockhausen's Carré.

[5] He was influenced by the tradition of the Second Viennese School, and his small oeuvre includes settings of poems by Hans Arp, Paul Claudel, Stefan George, and Pablo Neruda.

[1] His die glocken sind auf falscher spur after Hans Arp was premiered in 1970 with soprano Joan Carroll, cellist Siegfried Palm, pianist Aloys Kontarsky, Wilhelm Bruck, Christoph Caskel and the composer at the Saarländischer Rundfunk festival, "Musik im 20.Jahrhundert"[20][1] His string quartet Un vieux souvenir after Baudelaire's Les Fleurs du mal, composed from 1983, was premiered in 1985 in Cincinnati by the LaSalle Quartet.