Lecture Notes: Inharmonicity in Piano Tuning

Introduction to Inharmonicity

• Presented by Steve Howard at Howard Piano Industries.
• Inharmonicity is a concept used in piano tuning.
• Explains why pianos require octave stretching.

Understanding Partials and Overtones

• Partials are overtones present in a piano note.
• These are segments of a string when a piano key is pressed.
• Partials: First partial is half the string's length, second is a third, and so on.

Concept of Inharmonicity

• Inharmonicity results from stiffness in string segments.
• Shorter segments of a string are stiffer, affecting pitch.
• Stiffness causes overtones to be sharper than theoretical values.

Practical Example

• Demonstration: Shorter string segments are stiffer and affect pitch.
• Partials become sharper as they go higher.

Tuning Adjustments

• Tuning requires adjusting notes to be sharper or flat.
• Start tuning usually at A4 as the base reference point.
• Notes tuned sharper in higher registers to accommodate partials.
• Less stretching needed in lower registers.

Factors Affecting Stretch

• Amount of stretch varies based on piano size, model, and scaling.
• Longer or taller pianos have less inharmonicity.
• Bass strings are wound with copper to avoid excessively long strings.

Piano Size and Sound Quality

• Taller or longer pianos (e.g., grand pianos) have better bass sound.
• Shorter pianos have more inharmonicity, affecting sound quality.

Conclusion

• More discussion on inharmonicity and tuning in future videos.
• For questions, visit howardpianoindustries.com.