Koichi Sugiyama, a Japanese composer and conductor known for his music in the popular Dragon Quest video game franchise, died on Sept. 30 of septic shock, his office said. He was 90.

Sugiyama, who composed music for the hit video game franchise since its release in 1986, is considered to have played a key role in its boom and establishing the genre of game music with the release of related CDs and orchestral concerts.

Music from the Dragon Quest series was played during the opening ceremony of the Tokyo Olympics this July.