Per or PER may refer to:

Arvo Pärt (born 11 September 1935; Estonian pronunciation: [ˈɑrvo ˈpært]) is an Estonian classical composer and one of the most prominent living composers of sacred music. Since the late 1970s, Pärt has worked in a minimalist style that employs his self-invented compositional technique, tintinnabuli. His music also takes inspiration from Gregorian chant.

Pärt was born in Paide, Järva County, Estonia. A prolonged struggle with Soviet officials led him to emigrate with his wife and their two sons in 1980. He lived first in Vienna, where he took Austrian citizenship, and then re-located to Berlin. He returned to Estonia around the turn of the 21st century and now lives alternately in Berlin and in Tallinn.

Familiar works by Pärt are Cantus In Memoriam Benjamin Britten for string orchestra and bell (1977) and the string quintet "Fratres I" (1977, revised 1983), which he transcribed for string orchestra and percussion, the solo violin "Fratres II" and the cello ensemble "Fratres III" (both 1980).