Scored for flute, clarinet, harp, piano and vibraphone, and running about 10 minutes in duration, "Rain Spell" is one of the composer's pieces expressing his fascination with rain and the random flow of water (Rain Coming, Water-Ways, Riverrun, Waterscape, Rain Tree, Garden Rain, etc.), a theme also shared by one of Takemitsu's main influences Claude Debussy. Written for the Sound Space Ark in Tokyo, "Rain Spell" opens with isolated arpeggios and gentle flutterings like splashes of water. Strange multiphonics sound like electronic insects. The melodies become longer and more full of eerie effects accompanied by muted harmonics on harp and piano. These describe the deep "spell" woven by the rain more than the sound of falling rain itself, and that is the genius of Takemitsu's spiritual insight expressed in his art.