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SONOLOGIUMATLAS
Organology & Physical Acoustics 03

The Instrumentarium

Every instrument gets a graph connecting Hornbostel-Sachs taxonomy to acoustic physics: body geometry → resonant modes, string length → pitch, material composition → damping Q factor, and excitation method → timbre. We examine why an instrument is shaped this way and what that physical geometry makes possible acoustically.

Organology & PhysicsSmithsonian Open Access Collections

The Instrumentarium

Acoustic SynthesisForm & Resonant Modes
Hornbostel-Sachs: 321.322-71

The 'Betts' Stradivari Violin

Chordophone / Bowed Necked Lute · Cremona, Italy (1704)

Smithsonian Record

One of Antonio Stradivari's supreme golden-period violins, renowned for unmatched projection, rapid transient attack, and complex overtone reinforcement.

Acoustic Physics & Resonant Geometry

Resonant Cavity Modes
  • ▸A0 Helmholtz resonance (~275 Hz, near C#4/D4)
  • ▸B1- plate breathing mode (~460 Hz)
  • ▸B1+ longitudinal dipole mode (~550 Hz)
Material Damping (Q Factor)
Q = 68

Picea abies (Italian alpine spruce) top plate, Acer pseudoplatanus (flamed Balkan maple) back/ribs

Body Geometry

Arched top and back plates (15 mm catenary rise) with carved C-bouts and F-holes (length 74 mm)

Excitation & Timbral Signature

Continuous stick-slip friction via rosined horsehair bow generating Helmholtz corner wave

Rich harmonic overtone spectrum extending beyond 12 kHz, pronounced 'bridge hill' projection at 2.5–3.5 kHz

Organological Lineage & Evolution
  • Medieval Rebec→
  • Renaissance Fiddle (Lira da Braccio)→
  • Amati Classical School→
  • Stradivari Golden Period→
  • Modern Concert Setup
Form & Acoustic Resonance Synthesis

“Catenary plate arching curves and C-bout structural stress distribution shift plate eigenmodes away from wolf-tone dissonance into singing acoustic radiation.”