BIVALENCE XIII，for Two Flutes（2017）

Bivalence is the title I have given to a series of works for two of the same instruments that I began working on in 1997. The first work in the series was for two cellos and was followed by duos for violins，violas，clarinets，oboes，double basses，percussion，saxophones，trumpets，mandolins，voices and harps. The next work (XIII) in the series is the present work for two flutes，which was subsequently followed by works for recorders，bassoons and trombones to make a total of seventeen pieces to date. In all these works I have kept the use of special performance techniques as often used in contemporary music to a minimum，in no small measure because I have become rather fed up with music of this type that often seems like little more than a self-indulgent parade of contemporary techniques. If anything，these pieces have the character of studies. My aim in Bivalence XIII was not to pit the two flutes against each other but rather to allow them to collaborate in creating a thrilling musical narrative.
　　I first met the flautist Hiroshi Koizumi when we were students together some sixty years ago at Tokyo National University of Fine Arts and Music. He has been a close friend of mine all these years，during which I have worked with him extensively on solo pieces and concertos and in studio recordings of music for the cinema and television. I had long felt that I wanted to compose a work for him as part of this ongoing series. The first performance of the piece was given by Hiroshi Koizumi and his gifted pupil Naomi Oda. It is an incomparable pleasure for any composer to have their work interpreted by such outstanding performers and friends.