function [frequencies, durations, error, statistics] = ...
song(notes, tempo, key, steps, octaves, tune)
% SONG converts a simple text based musical note notation
% to frequencies & durations.
%
% SONG takes up to 6 input arguments.
% notes - A space delimited string of musical notes.
% tempo - The tempo of the song in beats per minute.
% key - A key signature.
% steps - Number of steps to raise or lower each note.
% octaves - Number of octaves to raise or lower every note.
% tune - Shift notes up or down.
% SONG returns up to 4 arguments.
% frequencies - A vector of frequencies for each note.
% duration - A vector of time durations for each note.
% error - A message indicating any error.
% An empty string if no errors detected.
% statistics - A vector containing statistics for the song.
% [Length Notes Min Max]
% Length - Length of the song in seconds.
% Notes - Number of notes in the song.
% Min - Lowest non-zero frequency in the song.
% Max - Highest frequency in the song.
%
% The format for the NOTES is as follows:
% [octave]note[[#]accidental][beats]
% Where:
% octave - A number specifying the octave. Default is 0.
% 0 represents the octave of middle C.
% note - A letter in the range A-G (and R or Z for a rest),
% that specifies the specific note.
% No default, the note must be specified.
% accidental - One of n, b or #, to indicate natural, flat, or sharp.
% Default is n, natural.
% Each accidental applies to one note only, and
% completely overrides the key signature for that note.
% A number can optionally proceed the accidental
% to indicate multiple or fractional sharps and flats.
% Default is 1.
% beats - A number greater than zero to indicate length of the
% note in beats. Default is 1.
% Each note must be seperated by a space.
%
% There are two formats for TEMPO as follows:
% The number of beats per minute. Default is 90.
% The tempo can be specified by name.
% The following names are recognized using the following tempos:
% 'Prestissimo' = 200 'Andante' = 90
% 'Vivacissimo' = 190 'Adagietto' = 75
% 'Presto' = 180 'Adagio' = 70
% 'Vivace' = 140 'Larghetto' = 60
% 'Allegro' = 130 'Lento' = 50
% 'Allegretto' = 120 'Largamente' = 40
% 'Moderato' = 110 'Larghissimo' = 20
%
% There are two formats for the KEY signature as follows:
% A comma delimited string of characters. Each letter can be either
% n, f or s to indicate natural, flat or sharp. The order of the
% notes is C,D,E,F,G,A,B.
% The key signature can be specified by name.
% The following names are recognized:
% 'C' &'Aminor' ='n,n,n,n,n,n,n'
% 'G' &'Eminor' ='n,n,n,s,n,n,n' 'F' &'Dminor' ='n,n,n,n,n,n,f'
% 'D' &'Bminor' ='s,n,n,s,n,n,n' 'Bb'&'Gminor' ='n,n,f,n,n,n,f'
% 'A' &'F#minor' ='s,n,n,s,s,n,n' 'Eb'&'Cminor' ='n,n,f,n,n,f,f'
% 'E' &'C#minor' ='s,s,n,s,s,n,n' 'Ab'&'Fminor' ='n,f,f,n,n,f,f'
% 'B' &'G#minor' ='s,s,n,s,s,s,n' 'Db'&'Bbminor' ='n,f,f,n,f,f,f'
% 'F#'&'D#minor' ='s,s,s,s,s,s,n' 'Gb'&'Ebminor' ='f,f,f,n,f,f,f'
% 'C#'&'A#minor' ='s,s,s,s,s,s,s' 'Cb'&'Abminor' ='f,f,f,f,f,f,f'
% 'Aharmonic' ='n, n,n,n,s,n,n'
% 'Eharmonic' ='n,s,n,s,n,n,n' 'Dharmonic' ='s,n,n,n,n,n,f'
% 'Bharmonic' ='s,n,n,s,n,s,n' 'Gharmonic' ='n,n,f,s,n,n,f'
% 'F#harmonic' ='s,n,s,s,s,n,n' 'Charmonic' ='n,n,f,n,n,f,n'
% 'C#harmonic' ='s,s,n,s,s,n,s' 'Fharmonic' ='n,f,n,n,n,f,f'
% 'G#harmonic' ='s,s,n,2s,s,s,n' 'Bbharmonic' ='n,f,f,n,f,n,f'
% 'D#harmonic' ='2s,s,s,s,s,s,n' 'Ebharmonic' ='f,n,f,n,f,f,f'
% 'A#harmonic' ='s,s,s,s,2s,s,s' 'Abharmonic' ='f,f,f,f,n,f,f'
% Default is the C major key.
%
% Each note can be raised or lowered a specified number of STEPS.
% Each step equals two semitones. Default is 0.
%
% The entire piece can be shifted up or down full or fractional OCTAVES.
% Default is 0, no shift.
%
% The TUNE of the entire song can be modified. The A above middle C is
% defined as 440Hz. This can be adjusted to any frequency, by shifting
% A4 up or down the specified number of Hz. Default is 0.
%
% Example:
% [sng.tune, sng.rhythm, sng.message, sng.stats] = ...
% song('c d e f g a b 1c2 r 1c b a g f e d c4','Allegro','C',0,0,0);
%
% song - version 1.0 Jon Raichek jraichek@mathworks.com
frequencies = [];
durations = [];
error = '';
statistics = [0 0 0 0];
middleC = 0.0;
A4 = 440.0;
r12 = power(2.0, 1.0/12.0);
AoffsetC = 9.0;
% Set default tune & A4
if nargin < 6
tune = 0.0;
end
if ~isnumeric(tune)
error = ['Tune "' tune '" must be a number.'];
return
end
A4 = A4 + tune;
% Set default octave
if nargin < 5
octaves = 0.0;
end
if ~isnumeric(octaves)
error = ['Octave "' octaves '" must be a number.'];
return
end
octaves = octaves - middleC;
% Set default steps & semitones
if nargin < 4
steps = 0.0;
end
if ~isnumeric(steps)
error = ['Steps "' steps '" must be a number.'];
return
end
semiTones = steps * 2.0;
% Set default key signature
if nargin < 3
key = 'C';
end
if ~ischar(key)
error = ['Key "' num2str(key) '" must be a string.'];
return
end
% Set default tempo & SPB
if nargin < 2
tempo = 90.0;
else
if ischar(tempo)
tempo = lower(tempo);
switch tempo
case 'prestissimo'
tempo = 200;
case 'vivacissimo'
tempo = 190;
case 'presto'
tempo = 180;
case 'vivace'
tempo = 140;
case 'allegro'
tempo = 130;
case 'allegretto'
tempo = 120;
case 'moderato'
tempo = 110;
case 'andante'
tempo = 90;
case 'adagietto'
tempo = 75;
case 'adagio'
tempo = 70;
case 'larghetto'
tempo = 60;
case 'lento'
tempo = 50;
case 'largamente'
tempo = 40;
case 'larghissimo'
tempo = 20;
otherwise
error = ['I do not know the tempo "' tempo, '"'];
tempo = 90.0;
end
end
end
secondsPerBeat = 60.0 / tempo;
if 0 > secondsPerBeat
error = ['The tempo "' num2str(tempo) '" is too slow.'];
secondsPerBeat = 60.0 / 90.0;
end
% Check notes
if nargin < 1
error = 'I will pick a song for you.';
[notes, ferror] = local_pickSong(-1);
if ferror
error = ferror;
end
end
if isnumeric(notes)
[notes, ferror] = local_pickSong(notes);
if ferror
error = ferror;
end
else
if strcmp(notes, 'random')
[notes, ferror] = local_pickSong(-1);
if ferror
error = ferror;
end
end
end
switch notes
case 'twinkle'
notes = ['c c g g a a g2 f f e e d d c2 g g f f e e d2 g g f ' ...
' f e e d2 c c g g a a g2 f f e e d d c2 '];
case 'jingle'
notes = ['g.5 g.5 g 1e 1d 1c g3 g.5 g.5 g 1e 1d 1c a3 z.5 a.5' ...
' b 1f 1e 1d b3 z.5 b.5 1g 1g 1f 1d 1e3 g.5 g.5 g 1e ' ...
' 1d 1c g3 g.5 g.5 g 1e 1d 1c a3 z.5 a.4 b 1f 1e 1d ' ...
' 1g 1g 1g1.5 1g.5 1a 1g 1f 1d 1c3 1g 1e 1e 1e2 1e 1e' ...
' 1e2 1e 1g 1c1.5 1d.5 1e3 z 1f 1f 1f1.5 1f.5 1f 1e ' ...
' 1e 1e.5 1e.5 1e 1d 1d 1e 1d2 1g2 1e 1e 1e2 1e 1e ' ...
' 1e2 1e 1g 1c1.5 1d.5 1e3 z.5 1f 1f 1f1.5 1f.5 1f 1e' ...
' 1e 1e.5 1e.5 1g 1g 1f 1d 1c3 '];
case 'b5intro'
notes = 'z.5 g.5 g.5 g.5 eb2 z.5 f.5 f.5 f.5 d4 ' ;
end
% Lookup standard key signatures
scale = '';
key = lower(key);
switch key
case {'cmajor', 'cmaj', 'c'}
key = 'n n n n n n n';
scale = ['c d e f g a b 1c2 r' ...
' 1c b a g f e d c4'];
case {'gmajor', 'gmaj', 'g'}
key = 'n n n s n n n';
scale = ['g a b 1c 1d 1e 1f# 1g2 r' ...
' 1g 1f# 1e 1d 1c b a g4'];
case {'dmajor', 'dmaj', 'd'}
key = 's n n s n n n';
scale = ['d e f# g a b 1c# 1d2 r' ...
' 1d 1c# b a g f# e d4'];
case {'amajor', 'amaj', 'a'}
key = 's n n s s n n';
scale = ['a b 1c# 1d 1e 1f# 1g# 1a2 r' ...
' 1a 1g# 1f# 1e 1d 1c# b a4'];
case {'emajor', 'emaj', 'e'}
key = 's s n s s n n';
scale = ['e f# g# a b 1c# 1d# 1e2 r' ...
' 1e 1d# 1c# b a g# f# e4'];
case {'bmajor', 'bmaj', 'b'}
key = 's s n s s s n';
scale = ['b 1c# 1d# 1e 1f# 1g# 1a# 1b2 r' ...
' 1b 1a# 1g# 1f# 1e 1d# 1c# b4'];
case {'f#major', 'f#maj', 'f#'}
key = 's s s s s s n';
scale = ['f# g# a# b 1c# 1d# 1e# 1f#2 r' ...
' 1f# 1e# 1d# 1c# b a# g# f#4'];
case {'c#major', 'c#maj', 'c#'}
key = 's s s s s s s';
scale = ['c# d# e# f# g# a# b# 1c#2 r' ...
' 1c# b# a# g# f# e# d# c#4'];
case {'fmajor', 'fmaj', 'f'}
key = 'n n n n n n f';
scale = ['f g a bb 1c 1d 1e 1f2 r' ...
' 1f 1e 1d 1c bb a g f4'];
case {'bbmajor', 'bbmaj', 'bb'}
key = 'n n f n n n f';
scale = ['bb 1c 1d 1eb 1f 1g 1a 1bb2 r' ...
' 1bb 1a 1g 1f 1eb 1d 1c bb4'];
case {'ebmajor', 'ebmaj', 'eb'}
key = 'n n f n n f f';
scale = ['eb f g ab bb 1c 1d 1eb2 r' ...
' 1eb 1d 1c bb ab g f eb4'];
case {'abmajor', 'abmaj', 'ab'}
key = 'n f f n n f f';
scale = ['ab bb 1c 1db 1eb 1f 1g 1ab2 r' ...
' 1ab 1g 1f 1eb 1db 1c bb ab4'];
case {'dbmajor', 'dbmaj', 'db'}
key = 'n f f n f f f';
scale = ['db eb f gb ab bb 1c 1db2 r' ...
' 1db 1c bb ab gb f eb db4'];
case {'gbmajor', 'gbmaj', 'gb'}
key = 'f f f n f f f';
scale = ['gb ab bb 1cb 1db 1eb 1f 1gb2 r' ...
' 1gb 1f 1eb 1db 1cb bb ab gb4'];
case {'cbmajor', 'cbmaj', 'cb'}
key = 'f f f f f f f';
scale = ['cb db eb fb gb ab bb 1cb2 r' ...
' 1cb bb ab gb fb eb db cb4'];
case {'aminor', 'amin', 'am'}
key = 'n n n n n n n';
scale = ['a b 1c 1d 1e 1f 1g 1a2 r' ...
' 1a 1g 1f 1e 1d 1c b a4'];
case {'eminor', 'emin', 'em'}
key = 'n n n s n n n';
scale = ['e f# g a b 1c 1d 1e2 r' ...
' 1e 1d 1c b a g f# e4'];
case {'bminor', 'bmin', 'bm'}
key = 's n n s n n n';
scale = ['b 1c# 1d 1e 1f# 1g 1a 1b2 r' ...
' 1b 1a 1g 1f# 1e 1d 1c# b4'];
case {'f#minor', 'f#min', 'f#m'}
key = 's n n s s n n';
scale = ['f# g# a b 1c# 1d 1e 1f#2 r' ...
' 1f# 1e 1d 1c# b a g# f#4'];
case {'c#minor', 'c#min', 'c#m'}
key = 's s n s s n n';
scale = ['c# d# e f# g# a b 1c#2 r' ...
' 1c# b a g# f# e d# c#4'];
case {'g#minor', 'g#min', 'g#m'}
key = 's s n s s s n';
scale = ['g# a# b 1c# 1d# 1e 1f# 1g#2 r' ...
' 1g# 1f# 1e 1d# 1c# b a# g#4'];
case {'d#minor', 'd#min', 'd#m'}
key = 's s s s s s n';
scale = ['d# e# f# g# a# b 1c# 1d#2 r' ...
' 1d# 1c# b a# g# f# e# d#4'];
case {'a#minor', 'a#min', 'a#m'}
key = 's s s s s s s';
scale = ['a# b# 1c# 1d# 1e# 1f# 1g# 1a#2 r' ...
' 1a# 1g# 1f# 1e# 1d# 1c# b# a#4'];
case {'dminor', 'dmin', 'dm'}
key = 'n n n n n n f';
scale = ['d e f g a bb 1c 1d2 r' ...
' 1d 1c bb a g f e d4'];
case {'gminor', 'gmin', 'gm'}
key = 'n n f n n n f';
scale = ['g a bb 1c 1d 1eb 1f 1g2 r' ...
' 1g 1f 1eb 1d 1c bb a g4'];
case {'cminor', 'cmin', 'cm'}
key = 'n n f n n f f';
scale = ['c 1d 1eb 1f 1g 1ab 1bb 1c2 r' ...
' 1c 1bb 1ab 1g 1f 1eb 1d c4'];
case {'fminor', 'fmin', 'fm'}
key = 'n f f n n f f';
scale = ['f g ab bb 1c 1db 1eb 1f2 r' ...
' 1f 1eb 1db 1c bb ab g f4'];
case {'bbminor', 'bbmin', 'bbm'}
key = 'n f f n f f f';
scale = ['bb 1c 1db 1eb 1f 1gb 1ab 1bb2 r' ...
' 1bb 1ab 1gb 1f 1eb 1db 1c bb4'];
case {'ebminor', 'ebmin', 'ebm'}
key = 'f f f n f f f';
scale = ['eb f gb ab bb 1cb 1db 1eb2 r' ...
' 1eb 1db 1cb bb ab gb f eb4'];
case {'abminor', 'abmin', 'abm'}
key = 'f f f f f f f';
scale = ['ab bb 1cb 1db 1eb 1fb 1gb 1ab2 r' ...
' 1ab 1gb 1fb 1eb 1db 1cb bb ab4'];
case {'aharmonic' 'aharm' 'ah'}
key = ' n n n n s n n';
scale = ['a b 1c 1d 1e 1f 1g# 1a2 r' ...
' 1a 1g# 1f 1e 1d 1c b a4'];
case {'eharmonic' 'eharm' 'eh'}
key = ' n s n s n n n';
scale = ['e f# g a b 1c 1d# 1e2 r' ...
' 1e 1d# 1c b a g f# e4'];
case {'bharmonic' 'bharm' 'bh'}
key = ' s n n s n s n';
scale = ['b 1c# 1d 1e 1f# 1g 1a# 1b2 r' ...
' 1b 1a# 1g 1f# 1e 1d 1c# b4'];
case {'f#harmonic' 'f#harm' 'f#h'}
key = ' s n s s s n n';
scale = ['f# g# a b 1c# 1d 1e# 1f#2 r' ...
' 1f# 1e# 1d 1c# b a g# f#4'];
case {'c#harmonic' 'c#harm' 'c#h'}
key = ' s s n s s n s';
scale = ['c# d# e f# g# a b# 1c#2 r' ...
' 1c# b# a g# f# e d# c#4'];
case {'g#harmonic' 'g#harm' 'g#h'}
key = ' s s n 2s s s n';
scale = ['g# a# b 1c# 1d# 1e 1f2# 1g#2 r' ...
' 1g# 1f2# 1e 1d# 1c# b a# g#4'];
case {'d#harmonic' 'd#harm' 'd#h'}
key = '2s s s s s s n';
scale = ['d# e# f# g# a# b 1c2# 1d#2 r' ...
' 1d# 1c2# b a# g# f# e# d#4'];
case {'a#harmonic' 'a#harm' 'a#h'}
key = ' s s s s 2s s s';
scale = ['a# b# 1c# 1d# 1e# 1f# 1g2# 1a#2 r' ...
' 1a# 1g2# 1f# 1e# 1d# 1c# b# a#4'];
case {'dharmonic' 'dharm' 'dh'}
key = ' s n n n n n f';
scale = ['d e f g a bb 1c# 1d2 r' ...
' 1d 1c# bb a g f e d4'];
case {'gharmonic' 'gharm' 'gh'}
key = ' n n f s n n f';
scale = ['g a bb 1c 1d 1eb 1f# 1g2 r' ...
' 1g 1f# 1eb 1d 1c bb a g4'];
case {'charmonic' 'charm' 'ch'}
key = ' n n f n n f n';
scale = ['c 1d 1eb 1f 1g 1ab 1bn 1c2 r' ...
' 1c 1bn 1ab 1g 1f 1eb 1d c4'];
case {'fharmonic' 'fharm' 'fh'}
key = ' n f n n n f f';
scale = ['f g ab bb 1c 1db 1en 1f2 r' ...
' 1f 1en 1db 1c bb ab g f4'];
case {'bbharmonic' 'bbharm' 'bbh'}
key = ' n f f n f n f';
scale = ['bb 1c 1db 1eb 1f 1gb 1an 1bb2 r' ...
' 1bb 1an 1gb 1f 1eb 1db 1c bb4'];
case {'ebharmonic' 'ebharm' 'ebh'}
key = ' f n f n f f f';
scale = ['eb f gb ab bb 1cb 1dn 1eb2 r' ...
' 1eb 1dn 1cb bb ab gb f eb4'];
case {'abharmonic' 'abharm' 'abh'}
key = ' f f f f n f f';
scale = ['ab bb 1cb 1db 1eb 1fb 1gn 1ab2 r' ...
' 1ab 1gn 1fb 1eb 1db 1cb bb ab4'];
otherwise
end
% Play a scale
if strcmp(notes, 'scale')
if isempty(scale)
scale = 'c d e f g a b 1c 1c b a g f e d c';
end
notes = scale;
end
% Parse key signature
cdr = strrep(key, ',', ' ');
keySig = [0 0 0 0 0 0 0];
currentToken = 0;
while ~isempty(cdr)
[car, cdr] = strtok(cdr); %#ok<STTOK>
if isempty(car)
break
end
currentToken = currentToken + 1;
badNote = ['I am not familier with the key signature ' ...
num2str(currentToken) ' "' car '". '];
if currentToken > 7
break
end
index = 1;
[modifier, isNumber, index, ferror] = local_getNumber(car, index);
if ferror
error = [badNote ferror];
return
end
if ~isNumber
modifier = 1.0;
end
[accidental, isAccidental, index, ferror] = ...
local_getAccidental(car, index);
if ferror
error = [badNote ferror];
return
end
if ~ isAccidental
error = [badNote 'No accidental provided.'];
return
end
keySig(currentToken) = accidental * modifier;
if index <= length(car)
error = [badNote 'Extra stuff at end.'];
return
end
end
% Parse notes
cdr = notes;
currentToken = 0;
while ~isempty(cdr)
[car, cdr] = strtok(cdr); %#ok<STTOK>
if isempty(car)
break
end
currentToken = currentToken + 1;
index = 1;
badNote = ['Note ' num2str(currentToken) ' "' car ...
'" is out of tune. '];
switch car(1)
case '%'
continue
case {'@', '$', '!'}
error = [badNote 'Reserved.'];
continue
end
[octave, isNumber, index, ferror] = local_getNumber(car, index);
if ferror
error = [badNote ferror];
break
end
if ~isNumber
octave = middleC;
end
[note, isNote, index, ferror] = local_getNote(car, index);
if ferror
error = [badNote ferror];
break
end
note = note - AoffsetC;
[number, isNumber, index, ferror] = local_getNumber(car, index);
if ferror
error = [badNote ferror];
break
end
[accidental, isAccidental, index, ferror] = ...
local_getAccidental(car, index);
if ferror
error = [badNote ferror];
break
end
if isAccidental
if isNumber
accidental = accidental * number;
end
[beats, isNumber, index, ferror] = local_getNumber(car, index);
if ferror
error = [badNote ferror];
break
end
else
if isNote
accidental = keySig(isNote);
end
beats = number;
end
if ~isNumber
beats = 1.0;
end
if 0 >= beats
error = [badNote 'That is a very short note.'];
continue
end
if index <= length(car) && car(index) == '/'
error = [badNote 'Reserved.'];
while index <= length(car)
if car(index) == '%'
break
end
index = index + 1;
end
end
if index <= length(car) && car(index) ~= '%'
error = [badNote 'Extra stuff at end of note.'];
end
if isNote
frequency = power(r12, note+accidental+semiTones) * ...
A4 * ...
power(2, octave+octaves);
else
frequency = 0.0;
end
duration = beats * secondsPerBeat;
frequencies = [frequencies frequency]; %#ok<AGROW>
durations = [durations duration]; %#ok<AGROW>
end
% Collect statistics
statistics = [sum(durations) length(frequencies)];
if isempty(nonzeros(frequencies))
statistics = [statistics 0];
else
statistics = [statistics min(nonzeros(frequencies))];
end
if isempty(frequencies)
statistics = [statistics 0];
else
statistics = [statistics max(frequencies)];
end
return % End of song()
function [number, isNumber, next, error] = ...
local_getNumber(numberString, index)
% LOCAL_GETNUMBER extracts a number from a note.
%
% number - The Number.
% isNumber - 0: The was no number, 1: There was a number
% next - Index to first char after the number.
% error - Error message.
number = 0.0;
isNumber = 0;
next = index;
error = '';
if length(numberString) < index
return
end
% Number Format: [+|-]{0-9}[.]{0-9}
sign = 1.0;
if numberString(index) == '+'
sign = 1.0;
index = index + 1;
elseif numberString(index) == '-'
sign = -1.0;
index = index + 1;
end
if length(numberString) < index
error = 'Bad number, need more than a sign.';
next = index;
return
end
while numberString(index) == '0' || numberString(index) == '1' || ...
numberString(index) == '2' || numberString(index) == '3' || ...
numberString(index) == '4' || numberString(index) == '5' || ...
numberString(index) == '6' || numberString(index) == '7' || ...
numberString(index) == '8' || numberString(index) == '9'
digit = 0;
if numberString(index) == '1', digit = 1; end
if numberString(index) == '2', digit = 2; end
if numberString(index) == '3', digit = 3; end
if numberString(index) == '4', digit = 4; end
if numberString(index) == '5', digit = 5; end
if numberString(index) == '6', digit = 6; end
if numberString(index) == '7', digit = 7; end
if numberString(index) == '8', digit = 8; end
if numberString(index) == '9', digit = 9; end
number = (number * 10) + digit;
index = index + 1;
if length(numberString) < index
break;
end
end
if length(numberString) < index
next = index;
number = number * sign;
isNumber = 1;
return
end
fraction = 0.1;
if numberString(index) == '.'
index = index + 1;
if length(numberString) < index
next = index;
number = number * sign;
isNumber = 1;
return
end
while numberString(index) == '0' || numberString(index) == '1' || ...
numberString(index) == '2' || numberString(index) == '3' || ...
numberString(index) == '4' || numberString(index) == '5' || ...
numberString(index) == '6' || numberString(index) == '7' || ...
numberString(index) == '8' || numberString(index) == '9'
digit = 0;
if numberString(index) == '1', digit = 1; end
if numberString(index) == '2', digit = 2; end
if numberString(index) == '3', digit = 3; end
if numberString(index) == '4', digit = 4; end
if numberString(index) == '5', digit = 5; end
if numberString(index) == '6', digit = 6; end
if numberString(index) == '7', digit = 7; end
if numberString(index) == '8', digit = 8; end
if numberString(index) == '9', digit = 9; end
number = number + (digit * fraction);
fraction = fraction / 10.0;
index = index + 1;
if length(numberString) < index
break;
end
end
end
next = index;
number = number * sign;
isNumber = 1;
return % End of local_getNumber()
function [accidental, isAccidental, next, error] = ...
local_getAccidental(accidentalString, index)
% LOCAL_GETACCIDENTAL extracts the accidental from a note.
%
% accidental - Number of semitones from the natural note.
% isAccidental - 0: The was no accidental, 1: There was an accidental
% next - Index to first char after the accidental.
% error - Error message.
accidental = 0.0;
isAccidental = 0;
next = index;
error = '';
if length(accidentalString) < index
return
end
% accidental is the number of semitones from the natural note
switch accidentalString(index)
case {'n', 'N'}
accidental = 0.0;
isAccidental = 1;
case {'b', 'f', 'F'}
accidental = -1.0;
isAccidental = 1;
case {'#', 's', 'S'}
accidental = 1.0;
isAccidental = 1;
otherwise
accidental = 0.0;
isAccidental = 0;
end
if isAccidental
next = index + 1;
end
return % End of local_getAccidental()
function [note, isNote, next, error] = local_getNote(noteString, index)
% LOCAL_GETNOTE extracts the note.
%
% note - Number of semitones from C.
% isNote - 0:Rest, 1:C, 2:D, 3:E, 4:F, 5:G, 6:A, 7:B
% next - Index to first char after the note.
% error - Error message.
note = 0;
isNote = 0;
next = index;
error = '';
if length(noteString) < index
error = 'There is no note.';
return
end
% note is the number of semitones from C
switch noteString(index)
case {'A', 'a'}
note = 9.0;
isNote = 6;
case {'B', 'b'}
note = 11.0;
isNote = 7;
case {'C', 'c'}
note = 0.0;
isNote = 1;
case {'D', 'd'}
note = 2.0;
isNote = 2;
case {'E', 'e'}
note = 4.0;
isNote = 3;
case {'F', 'f'}
note = 5.0;
isNote = 4;
case {'G', 'g'}
note = 7.0;
isNote = 5;
case {'R', 'r', 'Z', 'z'}
isNote = 0;
otherwise
error = 'I only know the notes A-G and rests';
return
end
next = index + 1;
return % End of local_getNote()
function [ditty, error] = local_pickSong(pick)
% LOCAL_PICKSONG picks a song.
%
% ditty - Name of selected or random song.
% error - Error message.
error = '';
if pick < 0
c = clock;
pick = rem(round(c(6)*1000), 3);
end
switch pick
case 0
ditty = 'twinkle';
case 1
ditty = 'jingle';
case 2
ditty = 'b5intro';
otherwise
ditty = 'scale';
error = 'I never heard of that song, how about a nice scale?';
end
return % End of local_pickSong()
