Tonewood refers to specific wood varieties used for woodwind, percussion, or acoustic stringed instruments. The word implies that certain species exhibit qualities that enhance acoustic properties of the instruments, but other properties of the wood such as aesthetics and availability have always been considered in the selection of wood for musical instruments. According to Mottola's Cyclopedic Dictionary of Lutherie Terms, tonewood is:Wood that is used to make stringed musical instruments. The term is often used to indicate wood species that are suitable for stringed musical instruments and, by exclusion, those that are not. But the list of species generally considered to be tonewoods changes constantly and has changed constantly throughout history.
Varieties of tonewood As a rough generalization it can be said that stiff-but-light softwoods (i.e. from coniferous trees) are favored for the soundboards or soundboard-like surface that transmits the vibrations of the strings to the ambient air. Hardwoods (i.e. from deciduous trees) are favored for the body or framing element of an instrument. Woods used for woodwind instruments include African blackwood (Dalbergia melanoxylon) – also known as grenadilla – used in modern clarinets, oboes, and wooden concert flutes. Bassoons are usually made of hard maples, especially Norway maple (Acer platanoides), but sometimes palisander and rosewoods (Dalbergia spp.) is used in older or French-system bassoons. Wooden flutes, recorders, oboes, and early clarinet-like wind instruments of the Baroque and Classical periods may be made of various hardwoods, such as pear (Pyrus spp.), boxwood (Buxus spp.), or ebony (Diospyros spp.).
Softwoods Spruce is often used in the soundboards of instruments from the lute, oud, violin, viol, mandolin, guitar, and harpsichord families; as well as the piano. Spruce is particularly suited for this use because of its high stiffness-to-weight ratio. Commonly used varieties are Sitka/Alaskan spruce (Picea sitchensis), Adirondack/Red spruce (Picea rubens), Engelmann spruce (Picea engelmannii), and Picea abies (variously known as Norwegian, German, Alpine, Italian, or European spruce). Cedar has since the 1950s been used in the tops of classical guitars (Western red cedar (Thuja plicata), although not a true cedar) and to a lesser but growing degree in steel-string acoustic guitars. Also, genuine Lebanon cedar wood is used today in Crete, Syria, and Anatolia region for several traditional musical instruments, like the lyre. Although a softwood, cypresses such as Mediterranean cypress (Cupressus sempervirens) are used on the back and sides of flamenco guitars (guitars' back and sides by vast majority are of hardwoods), the distinction between flamenco and classical guitars only became apparent when makers started marketing their lower priced, snappy sounding, and thinner topped cypress guitars for the players of flamenco since Antonio de Torres – the progenitor of the modern classical guitar – did not differentiate between them constructionally. Yew was once as common as maple for the bowls of lutes and theorbos. Other softwoods, such as redwoods and Douglas fir have been used to a limited degree. Redwood is not used commonly for guitars with steel strings, but has been used for classical guitars.The Acoustic Guitar Guide, p63
Hardwoods Maple, especially Norway maple and sycamore maple, is traditionally used for the backs and sides of violin family instruments. One variation, the Bosnian maple, is probably the maple used by the Cremonese violin makers such as Antonio Stradivari and Giuseppe Guarneri. Maple is also frequently seen in acoustic guitars and mandolins. Most Fender electric guitars feature maple necks. Variations of maple (commonly lumbers with highly figured flames, quilts, or birdseye features) are highly sought after for the back and ribs of violin family instruments and their veneers are used on some of the tops of electric guitars for looks. The pinblock, bridges, and action components of the grand piano are usually made of maple or of beech. Mahogany may be used in the tops (although acoustically not optimal) of some guitars as well as the back, sides, and necks of instruments of the mandolin and guitar families. Mahogany may also be used for the solid bodies of electric guitars, such as the Gibson Les Paul. For lack of availability, other similar woods are used as mahogany replacements, such as Australian red cedar, Indonesian mahogany, African mahogany (Khaya), meranti (Lauan), kauri (Agathis), Nato (mora spp.), sapele, sipo (Entandrophragma utile), nyatoh, and okoume. Some of these alternatives are mahogany family timbers. Rosewoods are very often used in the back and sides of guitars and mandolins and fretboards on guitars. The most sought-after variety, Brazilian rosewood (Dalbergia nigra), has become scarce and expensive because of high demand, limited availability, and strict trade restrictions such as embargoes and CITES regulations. However, in August 2019, CITES announced an exception for rosewood used in musical instruments. The most widely used rosewood used currently is East Indian rosewood, often paired with a spruce top for steel string guitars and with spruce or cedar for classical guitars. Another rosewood, cocobolo, is used in some high-end clarinets and guitars. Rosewoods are also the wood of choice for marimba bars. Indian laurel is a more inexpensive, sustainable alternative to rosewood that, since the latter's temporary CITES ban, has come into use for guitar fretboards for its similar tone, feel, strength, durability, and appearance. Koa is traditionally used for ukuleles. Koa is also used for steel string guitars mostly for its beauty and compressed dynamic range. Ebony is also often used in many types of instruments for fingerboards, tailpieces, tuning pegs, and so forth for its attractive jet-black appearance, smoothness to the touch, hardness, and wear resistance. Several varieties of ebony are used. Ebony is often dyed to make it appear more uniformly black than the natural wood, which sometimes shows brown streaks. Paubrasilia, commonly called Pernambuco or Brazilwood, is the most sought-after material for the bows of classical stringed instruments, because of its effects on the tones they produce and the balance of stiffness and flexibility for the need of string players. Walnut is often used for the backs and sides of guitars and mandolin family instruments. Ash, alder, and basswood are commonly used for the bodies of electric guitars, ash for its light-colored, natural wood finishes, and alder and basswood for their uniform density, their ease of machining, and amenability to rapid finishing techniques.
Mechanical properties of tonewoods
Some of the mechanical properties of common tonewoods, sorted by density. Wood speciesρ Density
kg/m3J Hardness
NELR Flexural modulus
GPa𝜈LR Poisson's strain ratioF Flexural strength
MPaC Compressive strength
MPaS Shrinkage
Volume
%R Sound radiation
coefficientD Rigidity
3mm plate