İlhan Usmanbaş (23 October 1921 – 30 January 2025) was a Turkish contemporary classical composer who was trained and recognised internationally.

His maths teacher, a lover of music, advised Usmanbaş to give up the career that he had planned for himself: "We have enough engineers in Turkey.

[3] In 1942, he transferred to Ankara State Conservatory, where he went on to study in the Department of Musical Composition,[2] under members of the Turkish Five – Rey, Ahmet Adnan Saygun, Hasan Ferit Alnar, Ulvi Cemal Erkin, and Necil Kazım Akses – and David Zirkin.

At the time, he discovered the score of Alban Berg's Wozzeck in the library, and started to study and perform the works of other contemporary composers.

In the years 1957 and 1958, he was again in the United States on a Rockefeller fellowship, where he had the opportunity to meet many composers,[2] including Milton Babbitt, Henry Cowell and Morton Feldman.

[4] Usmanbaş published books and translations, and wrote congress programs and articles during his long years as a lecturer of musical composition.

He translated works in to Turkish, especially André Hodeir's Les Formes de la Musique as Müzik Türleri Ve Biçimleri ,[7][10][11] and Short History of World Music by Curt Sachs as Kısa Dünya Musikisi Tarihi.

[2][4][14] She died on 3 February 2022 at the age of 99 in a nursing residence that the couple had donated to,[citation needed] and where they had lived for eleven years at the time.