Not all pieces written after that need quite such a large orchestra, but concert halls had become bigger and composers had got used to a bigger variety of sounds. Later composers sometimes added all sorts of unusual instruments: wind machine, sandpaper block, bottles, typewriter, anvils, iron chains, cuckoo, Swannee whistle etc. None of these are normal orchestral instruments. Sometimes a piano is used in the percussion section, e.g. Igor Stravinsky used one in "Petrouchka". Sometimes voices are also used.