Thursday, March 10, 2016

Cello and String Bow Characteristics

The cello is the second-largest instrument in the string family. The bow used by a cellist has the same basic properties as other instruments in the string family, with the exception that the bow has a greater diameter and thickness. The dimensions of the bow add to the characteristic sound and performers try out several different bows before settling on the bow that works best for them.

The strings on the bow create friction and cause the strings on the cello to vibrate. The vibration is what creates the sound of the cello by reverberating inside the cello's chamber, which acts as an acoustic amplifier. Composers should know the parts of the bow since this helps them communicate accurately to the performer when discussing specific playing techniques.

Camlen

The camlen is the curved portion of the bow that goes inward toward the hairs of the bow. Camlen is typically made from a type of wood called Pernambuco that provides a resilient, flexible and lightweight material allowing a string player to play vigorously when necessary. Toward the bottom of the bow is the frog, that contains the ferrule and pearl eye. The performer lightly holds the frog with the fingers on their right hand. A cello stick typically ranges between 17.5 inches and 28 inches depending on the size of the cello. A full-sized cello will use the larger bow. The camlen is longer on a cello than that of a violin or viola.

Point

The cellos point is placed at the top of the bow and refers to the tip of the head. The point consists of a head plate made of metal or ivory and serves to protect the tip from damage. The hairs of the bow are attached to the head plate and connect to the end of the bow's stick. The top of the bow curves downward into the head. Cello tips are thicker than violin and viola tips.

Hairs

Bow hairs are typically made from horse hair or a synthetic material. In the past, strings were made from organic materials such as sheep intestines. Contrary to legend, the bow hairs were never actually made from cat intestines, but the name that was given to sheep intestines, "catgut,"  likely contributed to this rumor. Cello hairs are longer on the cello than that of the violin and the viola; however, the strings are smaller than those used on a bass. Cello bow hairs stretch along the length of the bow from the tip to the heel of the bow.

Frog

Minor adjustments to the tension of the bow occur at the frog. The frog consists of a metal screw, known as a ferrule, that the performer can adjust to tighten the strings. Additionally, a metal brace, called a ring wraps around the bow hairs to keep them in place and prevent the strings from coming loose. Cellists may refer to the frog as the heel. However, as a composer, you won't need to refer to the frog except when asking the performer to play close to the frog for a more forceful sound. In these cases, you can simply instruct the performer to play, "at the frog."