The Bow

• Published in: Handbook of Materials for String Musical Instruments pp. 583 - 637
• Main Author: Bucur, Voichita
• Format: Book Chapter
• Language: English
• Published: Switzerland Springer International Publishing AG 2016; Springer International Publishing
• Subjects: Ceramics & glass technology; Finite Element Computation; Macroscopic Aspect; Pernambuco Wood; Sound, vibration & waves (acoustics); Stringed Instrument; Timber & wood processing; Tropical Wood
• ISBN: 3319320785; 9783319320786
• DOI: 10.1007/978-3-319-32080-9_13

The structural elements of the modern bow used for the stringed instruments from the violin family are the bow stick, the hair, the frog, the button or the screw and the pad. The parameters which define the bow are the length, the weight, the balance, the playability and the potential for giving power to the sound and the aesthetics. The stick of the bow is made in pernambuco. The frog uses ebony, mother of pearl, ivory, silver and gold. Several alternative wood species or carbon fiber composites have been proposed, but the fine bows in pernambuco are preferred by the musicians. Physically the bow is a relatively simple device but requires a great skill in making it. The modes of vibration of the bow stick are bending, torsional and longitudinal. These modes are coupled to the stretched bow hair. The vibration of the head of the stick can couple to the modes of vibration of the hair, and furthermore, the hair string contact can either transfer energy to the radiating modes of the violin body or/and influence the generation of Helmholtz kinks in the string. Simulation of dynamic bow behaviour was performed with finite element computation. The vibration modes of the bow can influence the sound of the violin. Rosin, a natural product collected from longleaf pine combined with several other ingredients and applied to the bow hair, plays an important role in violin playing, and in other instruments of this family, by facilitating a clean attack of the played note.