Biwa music is a form of sung story-telling, with musical interludes and accompaniment. The expressive, dramatic nature of the instrument can emulate the various twists and turns of a story as it unfolds. The tales are most often stories originating from medieval Japanese literature, such as "The Tale of Heike", an account of the wars between the Minamoto and Taira clans in the 12th century. Epic conflagrations by the sea, ghost stories or the tragic deaths of doomed warriors are common themes, often expounded with references to Buddhist notions such as the impermanence of life.
The biwa arrived in Japan from China and Korea approximately 1300 years ago, with what is still Japan’s orchestra of the court, Gagaku. There is also evidence that other biwa instruments came from the Indian lute tradition. In the 9th century the Mõsõ (blind monks') biwa began to be used by blind musicians as an accompaniment to chanted religious texts and sutras. At the beginning of the 13th century, Heike biwa players began telling of tales of the rise and fall of the Taira clan in 12th C Japan.
The Biwa performance style has been refined over the years so that it can create scenes and enhance imagery in such a manner as to bring stories to dramatic life before the audience. It has a uniquely expressive sound with the potential to create drama by powerfully plucked sets of notes interspersed with quieter passages. Often, performance traditions use biwa music as interludes inserted between passages of sung narration.
The traditional instrument (about three feet long) has a body commonly made of a solid piece of hollowed-out mulberry (or rosewood, quince) and a paulownia wood soundboard, with silk strings stretched over fixed wooden and bamboo frets. The expressive sound gains character from the sawari effect, a buzzing percussive sound that originates from the top end of the fretboard at the 'nut', where strings resonate against a shaped piece of bamboo. The bachi (plectrum), strikes the strings in a sweeping motion whilst the other hand varies the string tension over the frets to produce a wide variety of pitches.