I have an obsession with strings. Violin strings, cello strings, bass strings, guitar strings, bass guitar strings. It’s amazing that marginally altering the materials or fabrication can transform how a string functions. I will not go into detail as to how strings are made and what they are made of here, as that would take too long, but this is the crash course. My intention in this first part is to inform the reader of the variational complexities inherent to strings made for musical instruments.
Strings can be a single wire of any number of metals, a strand of any number of polymers (like nylon), or a strand of wound intestine (cat, goat, sheep, human). A metal wire can be plain or stainless steel, or plated with chrome, tin, gold, even platinum.
Lower and mid-range pitched strings require more mass to achieve low enough pitches at playable tensions. Instruments like piano, harp, or fanned-fret instruments can add mass by increasing string length of lower strings. Instruments with uniform string lengths (like guitar and violin) can’t just add length to lower strings. However, even pianos cannot achieve the necessary mass for lower strings while still sounding like a piano by merely increasing string length. Strings either need to be denser or thicker. However, strings made of a single material quickly become too rigid as the string’s intended pitch lowers.
String makers solve this problem by wrapping a metal, polymer, or gut (intestine) core with one or more layers of metal. Because the wrapping is structurally decoupled (to varying degrees) from the core, the flexibility of higher pitched, non-wrapped strings is retained.
Here is where things get complicated (aka. interesting). Single metal wire strings can only really be made of steel due to the structurally inadequacies of other metals. But wrappings, which do not have this constraint, can be many forms of metal (steel, nickel, titanium, silver, gold alloy, tungsten, zinc, phosphor bronze, copper, aluminum, hydronalium, chrome steel, etc.). Instead of choosing wire vs. polymer vs. gut, now you have a choice matrix of the three basic types (plus any variations of each wherein!) vs. metal wrappings. Further, many strings use two or more layers. Upright bass strings can have up to five layers!
This choice matrix also does not take into account how the wrappings are applied. Violin family instrument string wrappings are ribbon/flat wound–meaning the wrappings are flat a smooth. Fretted instruments have in addition round wound wrappings. These wrappings range from fine to large. Also, round wound wrappings can be compressed into “half-rounds.”
Because the core is protected by the wrappings, manufacturers can then make the core into shapes other than the traditional cylinder (circular cross section). The most common of these in the fretted instrument world is the hexocore, which has a hexagonal cross section that enables a round metal wrapping to more closely structurally couple to the steel core. In the violin family world, metal and polymer cores can be made of intertwining fine strands rather than a single cord. A final dagger in the heart of simplicity is that these stranded cores can be made of any number of combinations of metals or polymers (occasionally both together!) and can be made up of any number of varying weave patterns.
In part two, I’m going to talk about the good ways and bad ways musicians typically evaluate and distinguish between string choices. I will show why the typical dichotometric models of describing strings (bright vs. dark, direct vs. subtle, quiet vs. loud, projecting vs. non-projecting, etc.) misleads consumers; and I will provide an alternate way to think about comparisons between strings (and comparisons between complexities in general).