Ken Hatfield Uses Needles to Change a Piano's Tone

When Harriet Cunningham met Ken Hatfield for her 2025 report, he had just spent two hours softening a grand piano's hammer felt. The instrument had been too overpowering for his client's living room. His next job, at the Sydney Opera House, called for a sound that could fill the Concert Hall.

This is not another name for tuning. Tuning sets pitch by adjusting string tension; voicing works on tone. Yamaha's manufacturing guide describes changing the hardness and resilience of hammer felt to shape the sound and balance neighbouring notes. Where a note has several strings, the hammer must also meet them evenly. Knowing where to loosen the felt, and how far to go, is skilled work.

The player's instructions may sound less technical. Kawai's 2025 film follows David Snyder asking for a strong bass and a warm middle register from his GX5 grand. A Piano Masters technician turns those preferences into hammer adjustments, with Snyder playing again to test each change. The manufacturer's account is promotional, but the exchange is tangible: a description of sound, a physical alteration, another attempt at the keyboard.

“The piano is a physical thing,” Hatfield told Cunningham. The arriving audience changes the humidity too. Preparing the instrument and trying it out belong together: technician and pianist need to hear what works in this room.