I received this CODE as the answer to my question but I cannot run it$?$ What is the problem?

THE CODE:

clear all

close all

clc

notes $=[\text{'}$A$\text{'}\text{'}$A$\text{'}\text{'}$E$\text{'}\text{'}$E$\text{'}\text{'}$E$\text{'}\text{'}$B$\text{'}\text{'}$C$\text{'}\text{'}$B$\text{'}\text{'}$A$\text{'}]$;

count $=[8000,4000,4000,4000,4000,4000,4000,4000,16000]$;

x $=[]$;

fs $=8000$;

overlap $=100$; $\%$ Define the overlap size

for i $=1$:length$($notes$)$

m $=$ count$($i$)$;

n $=0$:m$-1$;

$\%$ Determine frequency based on the note

switch $($notes$($i$))$

case $\text{'}$A$\text{'}$

f $=220$;

case $\text{'}$B$\text{'}$

f $=220*2^(2/12)$;

case $\text{'}$C$\text{'}$

f $=220*2^(3/12)$;

case $\text{'}$D$\text{'}$

f $=220*2^(5/12)$;

case $\text{'}$E$\text{'}$

f $=220*2^(7/12)$;

case $\text{'}$F$\text{'}$

f $=220*2^(8/12)$;

case $\text{'}$G$\text{'}$

f $=220*2^(10/12)$;

end

$\%$ Generate the waveform for the current note

y $=$ cos$(2*$ pi $*$ f $/$ fs $*$ n$)$;

$\%$ Generate ADSR envelope

ADSR $=[$

linspace$(0,1,$ round$(0\mathrm{.}005*$ m$)),...\%$ Attack

linspace$(1,0\mathrm{.}8,$ round$(0\mathrm{.}1*$ m$)),...\%$ Decay

linspace$(0\mathrm{.}8,0\mathrm{.}8,$ round$(0\mathrm{.}7*$ m$)),...\%$ Sustain

linspace$(0\mathrm{.}8,0,$ round$(0\mathrm{.}015*$ m$))\%$ Release

$]$;

$\%$ Ensure ADSR has the same length as $\text{'}$y$\text{'}$

ADSR $=$ ADSR$(1$:length$($y$))$;

$\%$ Create overlap section from previous note if applicable

if i $>1$

$\%$ Zero$-$pad the previous signal and current signal for overlap

y$\_$extended $=[$zeros$(1,$ length$($x$)-$ overlap$),$ x$($end $-$ overlap $+1$:end$)]$;

y$\_$current$\_$extended $=[$y$(1$:end $-$ overlap$),$ zeros$(1,$ length$($y$)-$ overlap$)]$;

$\%$ Overlap the signals

x $=$ x$(1$:end $-$ overlap$)+$ y$\_$current$\_$extended; $\%$ Overlapping part

x $=[$x$,$ y $.*$ ADSR$]$; $\%$ Concatenate the new signal

else

$\%$ First note, just apply ADSR

x $=[$x$,$ y $.*$ ADSR$]$;

end

end

$\%$ Play the sound

soundsc$($x$,$ fs$)$;