Arvo Pärt (Estonian pronunciation: [ˈɑrvo ˈpært]; born 11 September 1935) is an Estonian composer of contemporary classical music. Since the late 1970s, Pärt has worked in a minimalist style that employs tintinnabuli, a compositional technique he invented. Pärt's music is in part inspired by Gregorian chant. His most performed works include Fratres (1977), Spiegel im Spiegel (1978), and Für Alina (1976). From 2011 to 2018, and again in 2022, Pärt was the most performed living composer in the world, and the second most performed in 2019, after John Williams.
https://en.wikipedia.org/wiki/Arvo_P%C3%A4rt