# User:Don Guinn/PianoTuningScript

Note 'Verbs to build tables in Tuning' This script builds the tables in the Jwiki on piano tuning. Accessed from Essays/PianoTuning f1 beats f2 Calculates the number of beats per second heard when frequencies f1 and f2 are played together f1 cent f2 Gives the difference between frequencies f1 and f2 in cents Temperament_Octave The first table of fundamental frequencies and harmonics Beats The second table showing beats for 1 hz frequency Temperament_Procedure The third table showing the temperament tuning procedure Bottom of this script Four statements which build the beats for the check for A# These definitions are for the ideal string or pipe where the overtones follow exact multiples of the fundamental. In reality strings have stiffness, thickness and flaws which shift the overtones away from exact multiples. The stiffness shifts the overtones sharper, slightly more than exact multiples. The thickness of pipes shifts the overtones flatter, less than exact multiples. Chimes and drums have overtones which are nowhere near multiples For that reason two chimes are never played harmonically but melodically as the overtones clash so much that they sound awful together. Otherwise these shifts are neglegable in the mid-ranges of various instruments but become significant at the extremes. ) NB.*beats v Find the smallest beat between two frequencies NB. Example: NB. 220 beats 329.628 NB. The beats between A and E NB. Arguments: NB. x y - The frequencies NB. Return: NB. Three number list - NB. 0 - The smallest number of beats NB. 1 - The multiple or the frequency giving the beat for y NB. 2 - The multiple giving the beat for x NB. Logic: NB. The fundemental and the next eight harmonics are calculated NB. and the all combinations of differences are calculated. Then NB. the difference nearest zero is found. That number, along with NB. the frequency ratios are returned. If the number of beats is NB. negative thn the second note is flat of perfect. If positive NB. it is sharp of perfect. beats=:4 : 0"0 b=.--//(x,y)*/>:i.9 i=.($b)#:a i.<./a=.,|b (i{::b),>:|.i ) NB.*cent v Convert note pair frequencies to cents NB. from J-ottings 46: Musical J-ers by Norman Thomson NB. Arguments: NB. [ ] - The note frequencies NB. Return: NB. The interval from the left note to the right note in cents. cent=:1200&*@(2&^.)@%~ NB. 12%:2 to 1000 places just for fun, formatted for display Two_to_one_twelfth=:_75,\0j1000":(12(<.@%:)(2*10^12000x))%10x^1000x NB. Names of notes in the temperament notes=:<;._2 'F F# G G# A A# B C C# D D# E ' NB. Names of Intervals i=.'unison';'semi-tone';'second';'minor third';'major third' i=.i,'fourth';'tritone';'fifth';'minor sixth';'major sixth' intervals=:i,'minor seventh';'major seventh';'octave' NB. Indices to names and intervals used in the temperament temperament_intervals=:3 4 5 7 8 9 NB. When laying the temperament I do use the tritone as well, but NB. it sounds very rough. If it doesn`t sound rough then I know I NB. made a mistake. I just don`t include it as a temperament NB. interval as it`s not very useful. NB. simitone or half-step st=:12%:2 NB. Frequency of the first note of the temperament F=:220*st^_4 NB. Frequencies of the notes in the temperament frequencies=:F*st^i.12 NB. The Temperament Octave Temperament_Octave=:notes (4 : 0) ,;._2 (0 : 0) First Second Third Fourth Fifth Fundamental Harmonic Harmonic Harmonic Harmonic Harmonic ) y,(>x),.11j3":frequencies*/>:i.6 ) NB. Beats for various note intervals made to look pretty NB. Beats are proportional to the frequency. So, to build this NB. list, the frequency is set to one. multiply the beats for a NB. given interval by the frequency to get the the beats for NB. between a note and the note above in an interval. b=.1 beats st^temperament_intervals t=.21{."1]12j4":,.{."1 b t=.t,.([:;[:":&.>{.;'r';}.)"1|."1}."1 b t=.(>temperament_intervals{intervals),.t Beats=:(;'Interval ';'Beat Factor ';'Ratio'),'-',t NB. The temperament tuning list NB. Each line is a step. NB. The tuning and checks of the notes used in the temperament. NB. The first token in the line is t for tune and c for check. NB. The second and third token are the notes in the interval with NB. the first being the note already tuned and the second the one NB. being tuned or checked. temperament=:cut;._2 toupper 0 : 0 t a d t a e t e b c d b t b f# c a f# c d f# t f# c# c a c# c e c# t c# g# c b g# c d g# c c# g# t g# d# c a d# c f# d# t d# a# c d a# c f# a# c c# a# t a# f c g# f c a f c d f c c# f t f c c g# c c e c c a c c d# c t c g c g b c a# g c e g c c# g c d g ) NB.*Display_Temperament v Display the temperament with beats NB. Builds each line in the temperament procedure table Temperament_Step=:3 : 0 'c n'=.({.;}.)notes i. y select. c case. 7 do. m=.<'Check' case. 12 do. m=.<'Tune ' case. do. wd 'mb "Error" "Unidentified case"' end. b=.beats/f=.n{frequencies t=.(m,2{.&.>}.y),(12&{.&.>intervals{~|--/n),(0j3":&.><"0 f) NB. t=.t,(<([:;[:":&.>{.;'r';}.)"1|."1}."1 b),<7j3":{.b t=.t,<7j3":{.b ;:^:_1]0 3 2 5 1 4 6{t ) NB.*Temperament_Procedure n The temperament procedure table Temperament_Procedure=: 3 : 0 '' t=.Temperament_Step"1 temperament t=.'Tune octave A 220.000 tuning fork 0.000',t ' Action Note Using Beats','-',t ) NB. Definitions for last calculations NB. Calculate A# beats F# D C# {."1] 233.082 beats 184.997 293.665 277.183 NB. Raising A# by 0.5 hz {."1] 233.582 beats 184.997 293.665 277.183 NB. Lowering A# by 0.5 hz {."1] 232.582 beats 184.997 293.665 277.183 NB. Determine the error in cents 232.582 233.582 cent 233.082