Tonewood refers to any wood used to construct a musical instrument in order to convey sound. For stringed acoustical instruments the top, or soundboard, is most often made from spruce or cedar because of the wood’s high stiffness-to-weight ratio. Typical species of spruce used for acoustic guitar soundboards include Sitka (Picea sitchensis), Engelmann (Picea engelmannii), Adirondack or Red (Picea rubens), and European (Picea abies) also called Alpine, German, and Italian spruce. Western Red cedar (Thuia plicata) is used for soundboards due to the tight grain patterns, tonal responsiveness, and stability producing a warm, mellow tone. Because solid body electric guitars do not rely on a vibrating soundboard to produce tone, neither spruce nor cedar is typically used in their construction.
A variety of hardwood and even some softwood species are used to produce solid body electric guitars. By far, the most common woods for guitar necks (acoustic and electric) are quarter sawn mahogany and quarter sawn maple. Quarter sawn lumber is more stable than flat sawn lumber making it more resistant to twisting and warping and thus more suitable for guitar necks. Admittedly, guitar manufactures like Fender have used flat sawn maple for their necks with excellent results for more than 50 years, but most luthiers prefer quarter sawn lumber, especially for highly figured woods which are less stable than their unfigured counterparts.
For electric guitars, there are several choices of tonewoods for the body of the instrument. Furthermore, the top and back woods are often different species as typified by the Gibson Les Paul which features a maple top and mahogany back. Some of the more popular tonewoods are listed below.
- Koa (Hawaii)
- Swamp Ash
- Black Acacia
- Black Korina
Fingerboards can be made from several different hardwood species, but the most widely used are ebony, rosewood, and maple. Ebony and maple produce the brightest sound while rosewood produces warmer tones. There are several different species of ebony, but Gabon ebony is the blackest and best recognized of the species. Similarly, there are many true species of rosewood (genus Dalbergia) including Brazilian rosewood, Indian rosewood, African blackwood, cocobolo, kingwood, and tulipwood. Brazilian rosewood is the most recognized and coveted wood for guitars, but overharvesting and deforestation have placed it on the CITES list of endangered species, and while still available in the U.S. under strict permit, it is very expensive costing nearly $100 per fingerboard.
Several hardwood species can produce undulating grain patterns which give the wood a three dimensional appearance called chatoyance. Figured wood is used in musical instruments purely for its aesthetic appeal. Trees that produce highly figured lumber are rare and command high prices. The logs are used to produce veneers, fine furniture, and musical instruments. Figured maple is the most common figured wood for stringed musical instrument and goes by many names including curly maple, flamed maple, tiger maple, and fiddleback maple. Curly maple is graded on a scale of A to AAAAA (also called master grade) according to figure intensity with good depth filling the entire board, frequency of curls, and color uniformity and lightness. Several maple species produce the flame figure including hard and soft maple species, but for musical instruments, three hard maple species are preferred; Acer saccharum (sugar maple, rock maple, hard maple) which is indigenous to the eastern U.S. and Canada, Acer macrophyllum (big-leaf maple) which ranges from northern California to the center of coastal British Columbia, and Acer pseudoplatanus (European maple, sycamore maple, false plane-tree) which is native to Europe. Soft maple species are acceptable for guitar bodies but should never be used as a neck wood due to their inherent instability and tendency to twist and warp.
In addition to flame, Western big-leaf maple is the only maple that produces the quilted figure. Trees that yield quilted maple grow almost exclusively in northwest Washington State making this wood somewhat rare and commanding premium prices for top graded boards.
Several species beside maple produce figure including walnut, cherry, mahogany, sapele, and bubinga. The figure may be described by various names including striped, pommel, and beeswing.