The 17-string koto (Japanese: 十七絃 or 十七弦, Hepburn: jūshichi-gen, "seventeen strings") is a variant of the koto with 17 strings instead of the typical 13.
The instrument is also known as jūshichi-gensō (十七絃箏), "17 stringed koto", or "bass koto" (although koto with a greater number of strings also exist). The jūshichi-gen was invented in 1921 by Michio Miyagi, a musician who felt that the standard koto lacked the range he sought in a traditional instrument.[1] His 17 string creation, sometimes described as a "bass koto", has a deeper sound and requires specialized plectra; traditional koto plectra are worn attached to the player's fingers, with which the strings are plucked. Though his original jūshichi-gen was considerably larger than a normal koto, 17 stringed koto of a similar size to the average koto are more common today, though they do not have as deep a sound as the larger version.[citation needed]
In 2000, the musician Naito Masako, a member of the Seiha faction of the Ikuta school, constructed a new version of the 17-string koto called poppukon (popcorn), finished in bright colours such as pink, yellow, or blue.[2]