Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Taiko means "drum" in Japanese (etymologically "great" or "wide drum"). Outside Japan, the word is often used to refer to any of the various Japanese drums ( wa-daiko, "Japanese drum", in Japanese) and to the relatively recent art-form of ensemble taiko drumming (sometimes called more specifically, kumi-daiko). The performances can last between 5 to 25 minutes and typically follow a jo-ha-kyu (beginning, middle, end/rapid, sudden, urgent, and emergency) structure, which means the performance will speed up significantly towards the grand finale. Japanese taiko drums have been developed into a wide range of percussion instruments that are used in both Japanese folk and classical musical traditions. Taiko, in general, are stick percussion instruments. With the exception of the kotsuzumi and ootsuzumi, all taiko are struck with bachi. They have heads on both sides of the drum body, and a sealed resonating cavity.