Japanese gagaku was established around the year 900, during the Heian era (794ｰ1192), and since then its traditional performances have been giving mainly at the Court (in Kyoto), Nanto (in Nara), and Shitennoji (in Osaka), known as Sanpogakuso (three main music institutes).
These three institutes of gakuso was received the patoronage of the Emperors and the nobility, especialy the Fujiwaras (the most influencial family at that time) . As a result, the social status of the performers raised greatly. But the Tennojigakuso could not enjoy such patronage, because it belonged to the Shitennoji Temple distant from the Court. Consequently, the social status of its performers was not so high.
By the way, the Shitennoji Temple was the oldest Buddist temple built by the Crown Prince Shotoku in 593 soon after the Buddism was introduced into Japan. And Osaka was the international center of art and culture in Japan which had been imported from China (Sui) and the Korean Peninsula (Samguk period - three states of Pakche, Silla and Koguryo). So the rpiests of the temple naturally became very familliar with foreign music and dance. After this the art and dance spread widely in Osaka and gradually towards the capital.
With such a tradition the performers of the Tennojigakuso were proud of their art and so eager to improve it, and after the establishment of the Sampogakuso they revaled those of the Court and the Nantogakuso.
Since ancient times Shitennoji Temple had annually held three big rites with shomyo (Buddist chant ) and religious services accompanied by gagaku music and dance; Shoryoe, the anniverssary of the death of the Crown Prince Shotoku ; and Nehane, a service to commemorate the passing of Budda into Nirverna; and Kyokuyoe, a service held to celebrate the introduction of the Buddist Scriptures. These major rites were really very important oppotunities for the Shitennoji performers. Kenko Yoshida, a very famous essayist in the14th century, referred to these rites and prased highly the performance of Tennojigakuso in his essay, Tsurezuregusa (writ. about 1336). In fact, the quality of the performance of Tennojigakuso was appreciated by the Court and the Nantogakuso.
A big civil warlasting for years, Ouninnoran, broke out in 1467 in Kyoto and its neighbourhood. Many performers in the capital and Nara ran away from the city and consequently gagaku was temporarily in state of crisis. The performers of the Tennojigakuso, however, did their best allthe while in order to preserve the tradition, though they were involved into the disorder. As the result, when the peace came at last towards the end of the16th century and the government was keen to revive gagaku, the performers of the Tennojigakuso were able to play a leading role.