Koudi

The koudi, also spelled kou di, is the smallest flute in the Chinese flute family and a unique type of dizi. Invented in 1971 by the dizi master Yu Xunfa, the koudi is typically made of bamboo, though it can also be crafted from materials like PVC or wood. The koudi produces an extremely high-pitched, bright, and piercing tone, with sound adjustments made by covering and uncovering holes with the thumbs. Its small size—only a few inches long—contributes to its distinct tonal qualities, making it a visually and sonically unique instrument in traditional Chinese music.

History of the Koudi

The koudi traces its origins back to prehistoric instruments made from animal bones, later evolving into bamboo-based designs. Although bamboo has been used to make flutes for thousands of years, the modern koudi as it is known today was only invented in 1971 by Yu Xunfa, who introduced it as a type of dizi flute capable of producing unique, high-pitched tones. The koudi’s design is inspired by ancient flutes like the “chi” and other traditional bamboo wind instruments that have been discovered in various historical sites across China, including tombs from the Han Dynasty.

Throughout Chinese history, bamboo flutes have undergone significant evolution. During the Qin and Han Dynasties, flutes such as the chi and xiao were prominent, often featuring multiple holes and serving as important melodic instruments for religious ceremonies, banquets, and other cultural occasions. The koudi’s lineage can be traced back to these instruments, but its modern form, with only two main holes and minimalistic construction, reflects a unique adaptation designed to meet the expressive needs of contemporary Chinese music.

Anatomy of the Koudi

The koudi has a very simple construction compared to other members of the Chinese flute family:

• Length: The koudi is typically only a few inches long, with the most common keys being D and G.
• Blow Hole: The koudi features a blow hole through which the player directs airflow, similar to other transverse flutes.
• Sound Holes: Unlike many flutes, the koudi has very few sound holes—usually just two main holes at the ends. Longer models may feature additional holes that provide extra tonal control.
• Material: Most koudi are made from bamboo, but versions made of PVC, wood, or even bone are also found. Bamboo, with its light weight and natural acoustic properties, is the preferred material for most players.

With its minimalistic design, the koudi’s pitch is altered by adjusting the coverage of the two holes using the musician’s thumbs, allowing for a range of notes and bright, high-pitched tones.

Types of Koudi

Several variants of the koudi have been developed to enhance its range and versatility:

• Two-Hole Koudi: The original koudi, designed by Yu Xunfa, features two main holes, making it simple yet effective for high-pitched melodies.
• Five-Hole Koudi: To expand its range, Yu Xunfa added three additional holes, resulting in the five-hole koudi, which allows for a broader variety of notes and more complex melodies.
• Seven-Hole Koudi: Some koudi have been modified further to include up to seven holes, enhancing the instrument’s chromatic capabilities and making it more versatile in different musical contexts.
• Other Variants: Some koudi have been modified with additional openings to facilitate transposition or with larger or smaller finger holes to adapt the tone and ease of playability. Other variants include the “scale mouth flute” and the “Ding flute,” each having unique structural modifications.

How to Play the Koudi

Playing the koudi involves using both thumbs and fingers to manipulate the coverage of the sound holes:

• The thumbs of both hands are used to cover the first and second main holes, allowing for pitch modulation by varying the amount of coverage.
• The player’s index finger, middle finger, and ring fingers may assist in stabilizing the flute and managing finger holes if additional holes are present.

For the best sound production, the player’s lips should align precisely with the blow hole, creating a small damper to control airflow. Tightening the lip muscles and maintaining steady air pressure are critical to producing the koudi’s characteristic high and bright tone. By adjusting mouth strength and changing the blowing angle, players can achieve a broad dynamic range, making the koudi capable of both soft, subtle notes and powerful, bright passages. The koudi’s tone is bright, clear, and whistle-like, making it suitable for lively, melodic music and the imitation of bird calls.

Maintenance of the Koudi

Maintaining the koudi is crucial to preserving its quality and performance:

• New Flute Preparation: For newly purchased koudi, the bamboo may be soaked in saltwater to remove excess moisture before being oiled. This helps protect the bamboo from cracking and maintains its integrity.
• Cleaning: After each use, any moisture should be removed from the flute to prevent mold or bad odors. The koudi can be wiped down with a cloth brush to ensure that no saliva remains inside.
• Storage: When not in use, the koudi should be stored in a protective cloth cover or flute box to protect it from direct sunlight and temperature changes. Bamboo flutes, in particular, are sensitive to extreme temperature shifts, which can cause warping or cracking.
• Long-Term Care: To avoid cracks, a “flute tube” (a small stick wrapped in cloth and soaked in oil) can be inserted into the flute during storage to keep it humidified. This helps maintain the integrity of the bamboo, especially in dry climates.