Krystof Eugeniusz Penderecki is a Polish composer who scored this piece, Threnody for the Victims of Hiroshima in 1960. In this piece, Penderecki experiments with extended instrumental techniques, tone clusters and other non-conventional uses of instruments which would inevitably influence not only other 20th Century composers, but no doubt experimental rock musicians such as Sonic Youth, Lydia Lunch and most obviously, Glenn Branca.
Penderecki penned several other pieces that I think are pretty brilliant, but this is his most famous and probably my favorite. This version is performed by the National Polish Radio Symphony Orchestra. Check it out and listen to it loud. Close your eyes and freak out your neighbors.