Papua New Guinea

Written by Icelandic composer Jón Leifs in 1964, the piece called Hekla, Op 52, requires four sets of rocks hit with hammers, steel plates, anvils, sirens, cannons and metal chains to play.

The smallest US state, Rhode Island (1,212 square miles), has a larger population than the largest US state, Alaska (663,300 square miles), with 1.055 million residents vs. 736,732.