The Imperial Symphony Orchestra, or the ISO, was the premier orchestra of the Galactic Empire. It was comprised of many of the Empire's most talented musicians. From approximately 15 BBY to 0 ABY, the prestigious group performed exclusively in the Core Worlds, as regions like the Mid Rim could not afford to host the orchestra for a variety of reasons. In approximately 5 BBY, the ISO began a five-year tour that promoted Imperial High Culture within the Core. In 0 ABY, about seven months after an Imperial defeat in the Yavin system, the ISO journeyed to the Mid Rim for a series of performances, as firmly-established New Order supporters had wiped away all previous impediments. The orchestra's Mid Rim tour was slated to include Neoclassical pieces favored by Emperor Palpatine.