1. The Science of Guitar
Arun Kumar

2. Evolution of guitars

3. SIHTAR (Persian) Kithara (Greek) Qitar (Arabic) Guitarra (Spanish)
Lute: Egyptian, Hittite, Greek, Roman, Turkish, Chinese, and other cultures.
Ancient Egyptian tomb painting depicting lute players, 18th Dynasty (c.1350 BC).
Hellenistic banquet scene from 1st Century AD, Hadda, Gandhara. Lute player far right
Renaissance lute (holding position).

4. T.D. Rossing: Center for Computer Research in Music and Acoustics (CCRMA), Stanford University

5. Classification
Acoustic
Electric
Electric-Acoustic

6. Types of acoustic guitars

7. Types of electric guitars

8. Component design

9. Mechanism of sound generation
Direct sound
(small fraction)

10. Transverse waves on a string
T - String tension
m - String linear density
c - Wave propagation velocity
Governing Equation
Nature of functions is arbitrary (eg. Sinusoidal or Impulsive waves of different shapes)
General solution

11. Superposition of wave pulses
Plucked strings

15. Time analysis of string motion

16. Classical guitar: Typical frequency spectrum

17. Vibration Modes of the body
Top plate
Bottom plate

18. Other vibration modes

19. Resonant Frequencies
Holographic interferograms of classical guitar at several resonant frequencies
Q is a measure of resonance sharpness

20. Influence of design and construction
Bridge: Strongest influence on sound quality
(followed by top plate thickness and struts)
Mass vs. Stiffening
Lower frequencies
Higher frequencies

21. Influence of design and construction
Lattice bracing of top plate
Struts thickest at bridge, tapering away further
Carbon fiber epoxy structs

22. Influence of design and construction
Examples of
Radial
Asymmetric
Bracing
Ramirez
(Spain)
Fleta
(Spain)
Eban
(USA)
Holographic interferograms in radially braced strut design (Eban)

23. Materials of construction
Neck: Mahogany or Rosewood
Reinforcing steel rod through the length
Top plate: Spruce or Redwood
Ribs/Struts: Rosewood or similar hardwood
Cedar, Pine, Mahogany, Ash, Elder, Maple: Popular Choices
Synthetic materials also in vogue: Fibre glass, polymers
But considered inferior in general

24. Bending of rosewood sheets for the guitar side
B.C.Bennet, Economic Botany, 70(1), 2016, pp. 49–63

25. B.C.Bennet, Economic Botany, 70(1), 2016, pp. 49–63

28. Mechanism of sound generation
Direct sound
(small fraction)

29. Electric Guitars

30. Electric Guitars – typical wiring diagram
Piezzo electric pick-up

31. Aesthetics in design Math Product Design Architecture Physics
Chemistry
Objectivity
Biology
Medicine
Psychology
Fine Arts
Subjectivity

33. In summary…. Guitar is a sophisticated, precision engineered product
Needs to meet complex technical requirements based on sound scientific principles
Sound output
Craftsmanship
Precision
Durability
And aesthetics
Visual appeal
Touch and feel
Quality of sound