Virtual Koto
Pluck the 13 strings of the traditional Japanese zither to play beautiful Hira-joshi melodies.
Loop Recorder
Record up to 8 seconds of playing.
Not recording
✅ How to Play the Virtual Koto
- Click or tap any string to pluck it individually and hear its note.
- Click and drag your mouse or finger vertically across the strings to play a smooth glissando — sweeping up or down through all 13 strings rapidly.
- On desktop, press number keys 1 through 0, then -, = to trigger strings 1 through 13 from the keyboard.
- Use the Loop Recorder to capture a phrase and loop it — great for layering melodic patterns.
What is a Koto?
The Koto is one of Japan's most iconic and beloved musical instruments, widely regarded as the national instrument of Japan alongside the shamisen and shakuhachi. Dating back to the Nara period (710–794 CE), when it was introduced from Tang Dynasty China, the Koto has evolved over more than 1,300 years into its modern 13-string form. It consists of a long, narrow rectangular body approximately 180 centimetres in length, traditionally crafted from Paulownia wood — chosen for its resonance and light weight. Thirteen silk or nylon strings are stretched horizontally across this body, and each string is supported by a small, movable ivory or plastic bridge called a ji. By repositioning these bridges before playing, the performer tunes each string to the desired pitch.
The Koto is played by plucking the strings with picks worn on the thumb, index finger, and middle finger of the right hand, while the left hand presses or bends strings behind the bridges to alter pitch and add expression. This technique allows players to produce vibrato, slides, and microtonal ornaments that give Koto music its distinctly lyrical, flowing character. The Hira-joshi scale used in this virtual instrument — D, G, A, B♭, D, E♭, G, A, B♭, D, E♭, G, A — is the most commonly used pentatonic-based scale in classical Koto music. Its characteristic minor seconds create an instantly recognisable, contemplative sound that is central to traditional Japanese aesthetics.
The Koto has a remarkably broad musical range. In the classical tradition, it forms the core of sōkyoku (chamber music for Koto and shamisen) and appears in court music called gagaku. In the 20th century, composers like Michio Miyagi revolutionised the instrument by creating the 17-string bass Koto and composing pieces that blended Western harmony with Japanese melodic sensibility. Today the Koto appears in jazz fusion, ambient, and film scores worldwide — its plucked resonance lending an unmistakable warmth to any genre.
This virtual Koto uses the Web Audio API to synthesise each string's pluck in real time. A triangle wave oscillator captures the warm, woody body of the instrument, while a brief square-wave attack transient replicates the sharp click of the plectrum. A dynamic lowpass filter tracks the frequency over time, gradually dimming the higher harmonics as the note decays — exactly as a real Koto string does. The bridges in this instrument are positioned to reflect a characteristic Hira-joshi tuning curve, with the bridge positions forming a gentle diagonal across the body just as on a real instrument.
Frequently Asked Questions
What scale does this virtual Koto use?
This instrument uses the Hira-joshi scale (also related to In Sen), the most classic Japanese pentatonic tuning. Its defining characteristic is the use of minor second intervals (half steps) between certain degrees, which gives it that instantly recognisable Japanese melodic flavour. It is distinct from Western major and minor scales and sounds particularly beautiful when played with sweeping glissandos.
How many strings does a Koto have?
A standard Koto has 13 strings, which is what this virtual instrument replicates. There are also 17-string and 21-string Koto variants used in modern Japanese music, but the 13-string is the classical standard. Each string in the Hira-joshi tuning spans roughly three octaves from the lowest D to the highest A.
Can I play a glissando?
Yes — click and hold, then drag your mouse or finger across all the strings in one continuous motion. This produces a fast, sweeping glissando through all 13 notes. Upward drags (low to high) and downward drags (high to low) both work beautifully and are among the most expressive techniques in real Koto playing.