Mauch MIREX 2010

%

%CHORD2NOTES Convert chord symbol to list of constituent notes

% 

% [chordnotes, bassnote, success, errormessage] = chord2notes(chordsymbol, {verbose})

% 

% Converts a chord symbol to a cell array of note strings and a bassnote string.

%

% In the case of the 'no chord' symbol 'N' function returns an empty array

%

% Success = 1 if notes extracted from chordsymbol correctly, 0 otherwise.

% 

% If optional argument 'verbose' is 1, function prints any errormessage to 

% the screen.

% 

% calls:    getnoteinfo

%           parsenote

%           addshort2list

%           degree2note

% 

% returns:  chordnotes  (cell array of note strings)

%           bassnote (string)           

%           success (boolean)

%           errormessage (string)

%

%

% Author: Christopher Harte,  August 2005

% 

% Copyright: Centre for Digital Music, Queen Mary University of London 2005 

%

% This file is part of the C4DM Chord Toolkit.  

%

% The C4DM Chord Toolkit is free software; you can redistribute it and/or 

% modify it under the terms of the GNU General Public License as published 

% by the Free Software Foundation; either version 2 of the License, or

% (at your option) any later version.

%

% The C4DM Chord Toolkit is distributed in the hope that it will be useful,

% but WITHOUT ANY WARRANTY; without even the implied warranty of

% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

% GNU General Public License for more details.

%

% You should have received a copy of the GNU General Public License

% along with the C4DM Toolkit; if not, write to the Free Software

% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

%             

function [chordnotes, bassnote, success, errormessage] = chord2notes(chordsymbol, verbose)

% set verbose default to 0

if nargin < 2

    verbose = 0;

end

errormessage = '';

mainlist = '';

success = 1;

chordnotes = [];

bassnote = '';

% parse the chordsymbol

[rootnote,shorthand,degreelist,bass, success, errormessage] = getchordinfo(chordsymbol);

%if 'no chord' then return N

if (success == 1)

    if rootnote == 'N'

        chordnotes = [];

    else

        % combine shorthand and degreelist and obtain note names for each

        % degree

        if success

            [mainlist, success, errormessage] = addshort2list(shorthand, degreelist);

            if success

                % convert list of degrees to list of notes 

                [chordnotes,success,errormessage] = degrees2notes(mainlist,rootnote);

            end

        end

        % Now find the bass note

        if success

            if ~isempty(bass)

                [bassnote,success,errormessage] = degree2note(bass, rootnote);

                if success

                    ilength = length(chordnotes);

                    index = 1;

                    while index<=ilength

                        if char(bassnote) == char(chordnotes(index))

                            index = ilength +1;

                            contains = 1;

                        else

                            contains = 0;

                            index = index +1;

                        end

                    end

                    if contains == 0

                        chordnotes = [bassnote; chordnotes];

                    end

                end

            else

                bassnote = rootnote;

            end

        end

    end

end

if success == 0

    errormessage = [errormessage sprintf(['Error in chord2notes: Couldn''t convert chord"' chordsymbol '"\n'])];   

    if verbose ==1

       fprintf(1,errormessage);

    end

end