Arvo Pärt 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. The Arvo Pärt Centre, in Laulasmaa, was opened to the public in 2018.

Spiegel im Spiegel is a composition by Arvo Pärt written in 1978, just before his departure from Estonia. The piece is in the tintinnabular style, wherein a melodic voice, operating over diatonic scales, and tintinnabular voice, operating within a triad on the tonic, accompany each other. It is about ten minutes long.