Üstün Lütfi Yildirim, also known as Akkor, is a sound artist, composer, and performer. Born in Turkey, he holds a master's degree in Sonic Arts from Istanbul Technical University, Center for Advanced Studies in Music, earned in 2017.

He composed music and did sound design for the short film "Crowd" by Recep Akar, which won multiple awards, including Best Sound Design at the Focus International Film Festival in 2021.

He self-released two albums, "Uzak" in 2013 and "Durma" in 2020. In 2013, he collaborated with visual artist Uygar Demoglu on the installation project "Anonymous for Now," which was accepted into the Borusan Contemporary Art Collection.

In 2018, he participated in the 20th Red Bull Music Academy in Berlin.
He played his music live in venues including Zeiss-Großplanetarium, Sonar Festival, VII. International Sinop Biennial, and Babylon Istanbul.

Currently, he works as a freelance artist in Berlin. Besides his solo work, he collaborates with artists from different disciplines, mainly film, theater, contemporary dance, and installation.