WARSAW, Poland (AP) — Poland's leading composer and conductor, Krzysztof Penderecki died Sunday after a “long and serious illness,” sources close to his family said. He was 86.

In a statement emailed to The Associated Press, the Ludwig van Beethoven Association called Penderecki as “Great Pole, an outstanding creator and a humanist” who was one of the world's best appreciated Polish composers. The association was founded by Penderecki's wife, Elzbieta Penderecka, and the communique was signed by its head, Andrzej Giza.

A giant of contemporary music, Penderecki experimented with sound and form in the 1950s and 1960s, but then turned to classic forms like symphonies and oratorios like “Threnody for the Victims of Hiroshima” and “Seven Gates of Jerusalem.” His music was also used in movies, including Stanley Kubrick's “The Shining” and Martin Scorsese's “Shutter Island.”

He also taught young musicians and built an education and concert center in Luslawice in southern Poland, across the road from his home.

He also counted trees among his passions, and had tree species from around the world planted around his house.

Celebrated at home in Poland and abroad, he won four Grammy Awards over the course of his career, most recently taking home the award for best choral performance in 2016.