% compose.m lets you define a spectrum and hear the corresponding sound

spectrum_a=zeros(1,41600);
spectrum_a(440)=3;
a=ifft(spectrum_a);

spectrum_b=zeros(1,41600);
spectrum_b(880)=2;
b=ifft(spectrum_b);

spectrum_c=zeros(1,41600);
spectrum_c(1720)=1;
c=ifft(spectrum_c);

spectrum_d=zeros(1,41600);
spectrum_d(440)=3;
spectrum_d(880)=2;
spectrum_d(1720)=1;
d=ifft(spectrum_d);

sound([a a a a],41600)
pause
sound([b b b b],41600)
pause
sound([c c c c],41600)
pause
sound([d d d d],41600)
pause
sound([a a a a],41600)