What Cellos Are Made Of
Although cellos, over the years, have been made from a variety of materials, wood is still the predominant one. But the woods from which a cello is made vary, depending on the quality and the maker.
Cello Body Construction
"In general, instruments have spruce tops, maple back and sides. New cello makers are starting to play around with those woods a bit. But that's the established construction," affirms Carol Johnson, co-founder of Johnson String Instruments.
However, within that framework, there is a lot of variety. With the more expensive cellos, "you're going to get instruments in which the wood is specifically selected for certain patterns and body shapes," explains Carol.
Achieving the Cello's Body Shape
While the top and back of the body of the cello are traditionally hand-carved, a less expensive cello may be machine generated. But either way, the body's beautiful curves are made by heating the wood, and bending it around pre-made forms.
Internally, the sound and stability of the cello's body are enhanced with the bass bar and sound post.
Inside the Cello Body
The bass bar is an oblong piece of wood that is glued underneath the top of the cello body. The bass bar runs from the foot of the neck to just underneath the bridge. It reinforces the top of the body in order to support the tremendous tension of the strings (roughly equal to 80 pounds), and also helps transmit the internal vibration (sound) to the surface.
Like the bass bar, the sound post also sits on the inside of the cello, and serves two purposes. One is to reinforce the body strength of the cello. (The bass bar runs parallel to the G string and ends under the left foot of the bridge; the sound post sits underneath the right foot of the bridge.)
Additionally, the sound post helps to transmit the vibrations to the front of the cello (and to a lesser extent, the back).
Purfling: Attractive and Practical
On the top and back of most cellos is a decorative inlay called "purfling." Though purfling is quite esthetically pleasing, it also serves a useful purpose: it protects a cello against damage.
" . . . Any decently made acoustic cello is going to be delicate. It's a large box with several planes of wood that are carved quite thin. It's delicate regarding any sort of shocks or impacts," says Johnson String's Brian Kenny, Cello Technician.
Because it can stop cracks from forming, purfling actually limits the harm when a cello is bumped, dropped, knocked, or otherwise harmed. In addition, the purfling can protect a cello against traveling, weather, and other hazards.
Other Cello Features
The neck, pegbox and scroll are generally carved out of a single piece of wood, with the fingerboard glued on top. Holding the strings at the end of the cello's body is the tailpiece, which is traditionally made of ebony. It is not the only ebony to be found on a quality cello.
"You want to make sure that you have all ebony fittings, that your fingerboards are good ebony, that your pegs are good ebony. Because this is a material with a lot of strength, and it's not going to wear out easily," Ms. Johnson emphasizes.
Finally, there is the bridge, which can greatly affect the sound and playability of your cello, especially since it is not glued down, but is simply held to the cello's body by the tension of the strings. "You want to make sure that it's a high quality bridge, and that it's cut to fit the instrument (that is, at the feet of that bridge fits the instrument perfectly, and that there's no space underneath)," Carol advises.