The spreadhseet was originally written in 1986 on an AtariST and then, some years later, transferred onto a PC using Microsoft Works. The latest version presented here was re–written in 2012 in .odt (open document text) format using LibreOffice (v.3.4) and then converted to an Excel–compatible version.

The open-source programmes "LibreOffice and "OpenOffice" are free downloads and can be obtained from the following sites:

## USING THE SPREADSHEET: Layout, input, calculations and data

Spreadsheets can be considered as a grid of "cells" which contain a variety of information - text, data, equations etc. In our case this has been set up to form a table of calculations producing a series of results from the information supplied. The grid consists of a series of vertical columns (labelled alphabetically) and a series of horizontal rows (labelled numerically), so the first cell in the table would therefore be given the reference A1, with space allocated for a "Title" where you may write a few words concerning your specific sheet, e.g. harp name, stringing version, date etc.

The basic layout of the sheet is fairly straightforward, with horizontal rows assigned to the notes of the harp (from highest to lowest) and columns assigned to the various specific aspects concerning stringing and the results produced. These columns have been arranged in a logical order comprising three groups: columns giving the data for the calculations; columns showing the results of the calculations themselves; and (on the right-hand side) columns containing useful data values. I will briefly describe the use of these and their headings, in the order given above:

## Columns A to G: Data input

[A] Octv. (Octave) — This acts as a brief visual reminder of what octave the strings lie in. (NB: The actual note identity and value is listed under the Note and Pitch columns [D & E] to the right.)

[B & C] Density and Ts.Str. (Tensile Strength) - In these two columns information concerning the density and tensile strength of the chosen wire is entered. The spreadsheet has been written with the values for yellow brass inserted as the default setting, as this is likely to be the most commonly-used material. However these figures can be replaced by the appropriate data for any other string type desired, but please note the following:

In order to save the user from having to enter the same data figures over and over again for every string on the harp, I have written into the cells for these two columns a little instruction which will automatically copy the value written above it. This means that you only need to enter the values for the string's density and strength at the beginning; the figures will then be repeated down the column below this. Should you want to try more than one type of wire over the harp's range, the other wire's values can be entered at the point of changeover. You will now find that the table shows these amended values repeated in the cells below this point. Although this can save a lot of repetitive entering, please be aware that when a figure is entered into one of these cells, it will over-write the copy code in that cell. Therefore this automatic-copy feature may become increasingly disrupted as various combinations and positions are experimented with. This should not present too much of a problem, provided the user remains aware of it. The correct figures can always be entered manually or by copy/pasting.

[D & E] Note and Pitch Hz - Note and pitch values for the specific string are entered here. For column D I have used the standard nomenclature of the mainstream harp world, which numbers the octaves from the treble downwards (not from the bass upwards) with the octave number changing between the notes of E and F. As a benchmark, Middle C is 4th-octave C. You will notice that the default setting of the spreadsheet shows notes and frequency values for a harp tuned in the key of C major, with A pitched at 440 Hz. Other key scales or pitches can be overwritten if desired. (Other potentially useful pitch data can be found in columns N to AE at the right of the table.)

[F] Length - Enter the relevant string length in millimetres. (To convert inches to millimetres, multiply by 25.4.)

[G] Gauge - Enter the diameter of the string in millimetres.

## Columns H to L: Results of the calculations

[H] Stress — This figure is a calculation of the actual stress that the string is under, and is given in megapascals. Stress is also a major factor in the calculation of other important elements of this sheet, so it is the first thing that needs to be determined.

[I] Load — The force exerted by the specific string (which is the same as the tension of the string). At the bottom of the column (cell = I46) the total load exerted by the strings on the harp is displayed. (The results are given in kilograms force, but if you wish to use pounds force multiply the number by 2.205.)

[J] G/Rt.L (Gauge divided by the Square Root of the string Length) — Useful for giving an indication of the relative stiffness affecting the strings.

[K] %Strs. (Percentage of Stress) - Relates the stress of the string with the theoretical tensile strength of the particular string type. It therefore gives an indication of how close to breaking the specific string is likely to be.

[L] Ld./L (Load divided by string Length) — Useful when trying to assess how the feel of one string may compare to that of another

## Columns N to AE: Useful data values

These figures can be either copy/pasted or entered by hand into the relevant positions in columns B, C, D & E as desired.

[N & O] Wire Properties — Density and Ts.Str. These are typical values for some commonly used types of wire.

[Q, R & S] Key of C Major — Notes and Pitch values are given for both A=440Hz and A=415Hz.

[U, V & W] Key of G Major — Notes and Pitch values are given for both A=440Hz and A=415Hz.

[Y, Z & AA] Key of F Major — Notes and Pitch values are given for both A=440Hz and A=415Hz.

[AC, AD & AE] Chromatic Scale — Notes and Pitch values are given for both A=440Hz and A=415Hz.

Please Note: In order to prevent the sheet from being accidentally overwritten and equations and data fields becoming inadvertently changed, I have taken the precaution of write-protecting these important cells. This safeguards the critical areas of the sheet but still allows information to be entered where needed. The only areas requiring input are Columns A to G. However the automatic copy-code in columns B and C (used when inputting "Density" and "Ts.Str.") will be removed when overwritten (see note above). If you find that these columns become too disrupted, it may be worth starting with a "clean" sheet. A new copy of the original spreadsheet can always be downloaded whenever necessary. 