In an assignment A(:) = B, the number of elements in A and B must be the same.

Here I am trying to synthesis a song with the following sets of code but I am getting the error above at (line 62)

        song(n1:n2) = song(n1:n2) + tone; %<------- Insert the note into the vector

%create the song

theStrings(1).noteNumbers = [57 59 59 61 61 59 57 59 64 64 62 61 57 54 50 52 57 59 59 61 61 59 57 59 64 64 61 64 66 64 59 59 57 52 47 45 45 45 45 44 45 45 45 44 45 47 49 47 45 45 45 45 44 45 45 40 40 50 52 54 56 57 57 57 57 56 57 57 56 57 59 61 59 57 57 57 57 56 57 57 52 52 0 57 57 0 0 59 59 0 52 64 62 61 59 61 62 61 59 57 56 57 56 54 54 0 57 57 0 0 59 59 0 52 64 62 61 59 61 62];
theStrings(1).durations = [0.5 0.5 0.5 1.5 1 0.5 0.5 0.5 1.5 1 0.5 0.5 1 2 1 3 0.5 0.5 0.5 1.5 1 0.5 0.5 0.5 1.5 1 0.5 0.5 2 2 2 0.5 0.5 0.5 0.5 1.5 0.5 1 1 1 2 0.5 0.5 1 2 1 2 2 1.5 0.5 1 1 1 2 1 4 2 0.5 0.5 0.5 0.5 1.5 0.5 1 1 1 2 1 1 2 1 2 2 1.5 0.5 1 1 1 2 1 4 3 1 2 0.5 0.5 1 2 0.5 0.5 1 2 1 1 2 1 1 2 1 1 1 2 1 4 3 1 2 0.5 0.5 1 2 0.5 0.5 1 2 1 1 2 1 1];

theStrings(2).noteNumbers = [0 49 47 45 45 44 42 44 47 49 52 56 54 54 52 52 56 57 57 52 52 47 44 40 40 44 40 49 44 40 44 40 40 38 42 44 45 47 0 45 44 45 40 45 44 45 0 45 44 45 40 45 44 45 38 45 40 45 38 40 45 44 41 0 45 44 45 42 45 44 45 0 45 44 45 40 45 44 45 38 45 40 45 38 40 42 44 45 47 49 49 0 0 52 52 0 0 54 54 54 52 52 52 54 49 49 47 49 47 49 47 45 51 0 49 49 0 0 52 52 0 0 54 54 54 52 52 52];
theStrings(2).durations = [1 4 4 4 1.5 0.25 0.25 0.5 0.5 0.5 0.5 2 2 2 1 0.5 0.5 2 2 2 0.5 0.5 0.5 0.5 4 4 4 2 2 4 4 2 2 2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 2 1 1 1 1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1 1 1.5 0.5 1 1 2 0.5 0.5 1 2 0.5 0.5 1 2 1 1 2 1 1 2 1 1 1 2 1 4 3 1 2 0.5 0.5 1 2 0.5 0.5 1 2 1 1 2 1 1];

theStrings(3).noteNumbers = [0 44 45 42 45 44 45 42 42 44 40 44 42 44 40 40 42 38 42 40 42 38 40 35 40 35 28 30 30 28 26 28 28 28 33 33 33 28 33 33 33 33 28 28 21 21 28 28 26 26 28 29 30 30 25 25 26 26 28 30 30 0 0 28 28 0 0 26 26 28 30 25 18 25 25 26 26 26 28 30 25 18 0 28 23 16 0 26 26 28 30 25 18 25 25];
theStrings(3).durations = [1 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 2 3 1 4 4 1.5 0.5 2 4 4 4 4 4 4 2 2 3 1 3 1 3 1 3 1 2 2 3 1 3 1 4 3 1 2 0.5 0.5 1 2 0.5 0.5 1 2 2 4 1 1 1 1 4 4 1.5 0.5 2 1 1 1 1 1 1 1 1 2 2 4 1 1 1 1 4];

theStrings(4).noteNumbers = [0 45 44 42 40 33 40 45 45 45 40 33 33 40 45 45 45 40 33 33 40 45 45 45 40 33 33 40 45 45 45 40 35 37 40 38 40 40 37 40 38 38 33 40 37 35 37 42 40 37 37 35 38 38 40 42 44 42 33 37 42 45 44 32 35 40 44 45 45 45 44 42 44 45 37 44 42 40 40 40 40 33 38 40 42 38 40 42 44 42 33 37 42 45 44 32 35 40 44 45 45];
theStrings(4).durations = [1 4 4 4 4 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5 0.5 0.5 0.5 1 4 4 4 2 2 4 4 2 2 2 2 4 2 2 4 2 2 4 4 4 1.5 0.5 1 1 2 0.5 0.5 0.5 0.5 2 0.5 0.5 0.5 0.5 2 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 2 0.5 0.5 0.5 0.5 2 0.5 0.5 0.5 0.5 2 0.5 0.5 0.5 0.5 2 2];

fs = 44100;

spp = 0.25;% seconds per pulse, theVoices is measured in pulses with 4 pulsesper beat

% myMax = theVoices(1).startPulses(length(theVoices(1).startPulses)) + theVoices(1).durations(length(theVoices(1).startPulses));
% for i = 1:length(theVoices)
%     if ((theVoices(i).startPulses(length(theVoices(i).startPulses))+theVoices(i).durations(length(theVoices(i).startPulses))) > myMax)
%         myMax = theVoices(i).startPulses(length(theVoices(i).startPulses))+theVoices(i).durations(length(theVoices(i).startPulses));
%     end
% end

% Create a vector of zeros with length equal to the
% total number of samples in the entire song
n1 = 1;
spp = 0.25;% seconds per pulse, theVoices is measured in pulses with 4 pulsesper beat

myMax = theStrings(1).durations(length(theStrings(1).durations));
for i = 1:length(theStrings)
    if ((theStrings(i).durations(length(theStrings(i).durations))) > myMax)
        myMax = theStrings(i).durations(length(theStrings(i).durations));
    end
end

song = zeros(1, myMax*spp*fs);
% Then add in the notes

for i = 1:length(theStrings) % Cycle through each set of notes 
    % Convert data arrays to appropriate units

      for j = 1:length(theStrings(i).noteNumbers) % Cycle through each note in a set

          keynum = theStrings(i).noteNumbers(j);
          note = key2note(keynum,theStrings(i).durations(j)*spp);% create sinusoid of correct length to represent a single note

%         % Create the envelope
%         A = linspace(0, 0.2, (length(note)*0.15)); %rise 15% of signal
%         D = linspace(0.2, 0.3, ceil(length(note)*0.05)); %drop of 5% of signal
%         S = linspace(0.3, 0.8,(length(note)*0.6)); %delay of 60% of signal
%         R = linspace(0.8, 0,(length(note)*0.2)); %drop of 20% of signal
%         ADSR = [A D S R];
% 
%         tone = note .* ADSR; %"Enveloping" the note
        tone = note .* hanning(length(note));
        n2 = n1 + length(tone) - 1;
        song(n1:n2) = song(n1:n2) + tone; %<------- Insert the note into the vector
        n1 = n2 + 1;
%         song(locstart:locend) = song(locstart:locend) + tone;
    end
end
soundsc(song,fs);

%function to generate the note
function xx = key2note(keynum, dur)
% KEY2NOTE Produce a sinusoidal waveform corresponding to a
% given piano key number
% usage: xx = key2note (X, keynum, dur)
% xx = the output sinusoidal waveform
% X = complex amplitude for the sinusoid, X = A*exp(j*phi).
% keynum = the piano keyboard number of the desired note
% dur = the duration (in seconds) of the output note
fs = 44100;
tt = (1/fs):(1/fs):dur;
freq = 440*(2^((keynum -49)/12));%Frequency formula given in lab doc
xx = 0;

harmonic.amp = [0.1155 0.3417 0.1789 0.1232 0.0678 0.0473 0.0260 0.0045 0.0020];
harmonic.phase = [-2.1299 1.6727 -2.5454 0.6607 -2.0390 2.1597 -1.0467 1.8581 -2.3925];

for i = 1:9
    H = harmonic.amp(i) * exp(j*harmonic.phase(i));
    xx = xx + real(H * exp(j*2*pi*freq*tt*i));%Formula to create a sinusoid
end

% xx = real(exp(j*2*pi*freq*tt));%Formula to create a sinusoid
end

Answer 1

[Image Analyst]

hanning returns a column vector while note is a row vector. Try using a single quote at the end to transpose it:

tone = note .* hanning(length(note))';

[Sabrina Edelmann]

Ok, now I am having the problem that the index is exceeding the matrix index at the same line

[Walter Roberson]

I suspect your tone is longer than your existing song vector.

[Image Analyst]

Try

n2 = n1 + length(tone) - 1;
if n2 > length(song)
    n2 = length(song);
end
lastToneIndex = n2 - n1 + 1;
song(n1:n2) = song(n1:n2) + tone(1 : lastToneIndex);