The music for the video game Final Fantasy XV, developed and published by Square Enix as the fifteenth mainline entry in the Final Fantasy series, was composed primarily by Yoko Shimomura. Having previously worked on the Kingdom Hearts series, among various other titles, Final Fantasy XV was her first project for the series. Shimomura was brought on board the project in 2006, when it was a spin-off title called Final Fantasy Versus XIII, and stayed in her role during the game's ten-year development cycle. Her music, based around themes of "friendship" and "filial bonds", incorporates multiple musical genres, such as orchestral, bossa nova, and American blues. Several tracks, including the main theme "Somnus", feature Latin lyrics written by the game's original director Tetsuya Nomura.