Jim Woodhouse — jw12@cam.ac.uk
Cambridge University Engineering Department
Trumpington St
Cambridge CB2 1PZ, U.K.
Nicolas Lynch-Aird — lynchaird@yahoo.co.uk
The Old Forge
Burnt House Lane
Battisford
Suffolk IP14 2ND, U.K.
Popular version of paper ‘2pMU3’ String choice: Why do harpists still prefer gut?
Presented Wednesday afternoon, June 9, 2021
180th ASA Meeting, Acoustics in Focus
Classical guitarists have all abandoned traditional gut strings in favour of nylon, but harpists still prefer gut. Why is this? A study of the various limits on string choice for musical instruments has shown that the answer lies in a difference of “damping” in the strings, which is responsible for a difference in brightness of the sound.
When choosing a string for an instrument, the player knows the string length and the frequency it will be tuned to: their task is to choose the material and the diameter. The various different constraints on that choice can be summarised in a chart: a schematic version is shown here.
Schematic chart for choosing strings for musical instruments
The length and the frequency multiplied together defines the position on the horizontal axis. The player’s choice then consists of moving along a vertical line through that point, to choose a string diameter. They need to make a choice within the blue region, otherwise something will go wrong. The exact shape and position of this blue region depends on the choice of string material.
Obviously the string must not break. There are also upper and lower limits on the tension: if a string is too slack or too tight, it feels wrong to the player. Less obviously, the choice must lie beneath the dashed line labelled “damping too high”, otherwise the sound will become a dull thud rather than a ringing musical tone. This is where the harp differs from the guitar. Guitar strings stay well clear of the dashed line, but for the longer, lower-pitched strings of a harp, players want to use strings with very high tension so that the “feel” is right. But that pushes them towards the dashed line, and it is this damping limit that defines the practical limit on string choice. When the detailed charts are compared for nylon and gut strings, the dashed line is higher for gut. That gives a bit more “headroom” for the player’s choice, and allows them to choose a string that feels good under the fingers, while still having a satisfyingly bright and ringing tone.