- Robert Barclay
Term for changes in materials and characteristics over time, often causing deterioration of appearance as well as of acoustical and mechanical behaviours of musical instruments. Almost all materials degrade over time, and most deterioration can only be slowed, not arrested completely, much less reversed. Arguably, some instruments improve tonally with age, at least initially during a ‘breaking-in’ period, for reasons that are not always clear or convincing. However, this article focuses on six basic agents of deterioration, which normally work in combination.
During repair and restoration these effects of ageing are addressed by treatments such as consolidation, cleaning, adjustment, or replacement.
Mass-produced and synthetic materials dating from 19th-century industrialization are highly prone to deterioration because their long-term properties were insufficiently understood at the time of their development. For example, ebonite, a substitute for ebony in woodwind instruments, is a highly vulcanized natural rubber that emits sulphuric acid upon degradation. Other materials prone to rapid deterioration include celluloid and artificial leathers. Plastics, such as used in modern harpsichord jacks, can warp and their polymers break down, causing brittleness....