christopherh@1: % christopherh@1: %CHORD2MIDINOTES Generate MIDI note values for a given chord symbol christopherh@1: % christopherh@1: % [midinotes, success, errormessage] = chord2midinotes(chordsymbol, {verbose}) christopherh@1: % christopherh@1: % Obtains a set of midi note values for notes present in chord "chordsymbol". christopherh@1: % The voicing is built on the rootnote with all other intervals occuring christopherh@1: % above in number order unless a bass interval is specified. christopherh@1: % christopherh@1: % In the case of the 'no chord' symbol 'N' function returns midinote -1 christopherh@1: % christopherh@1: % Success = 1 if chord is converted correctly else 0. christopherh@1: % christopherh@1: % If optional argument 'verbose' is 1, function prints any errormessage to christopherh@1: % the screen. christopherh@1: % christopherh@1: % Returns: midinotes (array of integers) christopherh@1: % success (boolean) christopherh@1: % errormessage (string) christopherh@1: % christopherh@1: % christopherh@1: % % Author: Christopher Harte, March 2009 christopherh@1: % christopherh@1: % Copyright: Centre for Digital Music, Queen Mary University of London 2005 christopherh@1: % christopherh@1: % This file is part of the C4DM Chord Toolkit V2.0 christopherh@1: % christopherh@1: % The C4DM Chord Toolkit is free software; you can redistribute it and/or christopherh@1: % modify it under the terms of the GNU General Public License as published christopherh@1: % by the Free Software Foundation; either version 2 of the License, or christopherh@1: % (at your option) any later version. christopherh@1: % christopherh@1: % The C4DM Chord Toolkit is distributed in the hope that it will be useful, christopherh@1: % but WITHOUT ANY WARRANTY; without even the implied warranty of christopherh@1: % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the christopherh@1: % GNU General Public License for more details. christopherh@1: % christopherh@1: % You should have received a copy of the GNU General Public License christopherh@1: % along with the C4DM Toolkit; if not, write to the Free Software christopherh@1: % Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA christopherh@1: christopherh@1: % christopherh@1: function [midinotes, success,errormessage] = chord2midinotes(chordsymbol, verbose) christopherh@1: christopherh@1: % set verbose default to 0 christopherh@1: if nargin < 2 christopherh@1: verbose = 0; christopherh@1: end christopherh@1: christopherh@1: errormessage = ''; christopherh@1: mainlist = ''; christopherh@1: success = 1; christopherh@1: midinotes = 0; christopherh@1: christopherh@1: % parse the chordsymbol christopherh@1: [rootnote,shorthand,interval_list,bass, success, errormessage] = getchordinfo(chordsymbol); christopherh@1: christopherh@1: if success christopherh@1: christopherh@1: christopherh@1: %if 'no chord' then return -1 christopherh@1: if rootnote == 'N' christopherh@1: christopherh@1: midinotes = -1; christopherh@1: else christopherh@1: christopherh@1: % get root's pitchclass with respect to middle C and calculate absolute christopherh@1: % pitch of root in that octave christopherh@1: if success christopherh@1: christopherh@1: [rootpitchclass, success, errormessage] = note2pitchclass(rootnote); christopherh@1: christopherh@1: % midinote C4 = 60 so add pitchclass to calculate rootpitch christopherh@1: rootpitch = 60 + rootpitchclass; christopherh@1: christopherh@1: end christopherh@1: christopherh@1: christopherh@1: % combine shorthand and interval_list and obtain semitone values for each christopherh@1: % interval christopherh@1: if success christopherh@1: christopherh@1: [mainlist, success, errormessage] = addshort2list(shorthand, interval_list); christopherh@1: christopherh@1: if success christopherh@1: christopherh@1: [semitones,success,errormessage] = intervals2semitones(mainlist); christopherh@1: christopherh@1: % add rootpitch to obtain midinotes christopherh@1: chordpitches = semitones + rootpitch; christopherh@1: christopherh@1: end christopherh@1: christopherh@1: end christopherh@1: christopherh@1: % Now find the bass note christopherh@1: christopherh@1: if success christopherh@1: christopherh@1: % if we haven't got a bass interval then play the rootnote as the christopherh@1: % bassnote christopherh@1: if isempty(bass) christopherh@1: basspitchclass = rootpitchclass; christopherh@1: else christopherh@1: % otherwise convert the bassinterval to a note christopherh@1: [bassnote,success,errormessage] = interval2note(bass, rootnote); christopherh@1: christopherh@1: if success christopherh@1: christopherh@1: [basspitchclass, success, errormessage] = note2pitchclass(char(bassnote)); christopherh@1: christopherh@1: end christopherh@1: end christopherh@1: christopherh@1: if success christopherh@1: % calculate bass note so that it is in the octave below the christopherh@1: % rest of the chord i.e. add to C3 midinote 48 christopherh@1: basspitch = basspitchclass + 48; christopherh@1: christopherh@1: % Put midinote list together christopherh@1: midinotes = [basspitch, rootpitch]; christopherh@1: christopherh@1: for index = 1:length(chordpitches) christopherh@1: if chordpitches(index) ~= rootpitch christopherh@1: midinotes = [midinotes, chordpitches(index)]; christopherh@1: end christopherh@1: end christopherh@1: end christopherh@1: christopherh@1: end christopherh@1: end christopherh@1: christopherh@1: %alter pitches for chords with high roots christopherh@1: if rootpitchclass > 6 christopherh@1: midinotes = midinotes-12; christopherh@1: end christopherh@1: christopherh@1: end christopherh@1: christopherh@1: if success == 0 christopherh@1: errormessage = [errormessage sprintf(['Error in chord2midinotes: Couldn''t convert chord"' chordsymbol '"\n'])]; christopherh@1: if verbose ==1 christopherh@1: fprintf(1,errormessage); christopherh@1: end christopherh@1: end christopherh@1: christopherh@1: christopherh@1: