% notes.m sets up and plays single tones, a scale, and two chords

p=2^(1/12);                        % frequency multiplier between notes
t=0:(1/44100):1;                   % vector of time indices
a =sin(440*2*pi*t);          % define naturals and sharps
%as=sin(440*(p^1)*2*pi*t);
b =sin(440*(p^2)*2*pi*t);
%c =sin(440*(p^3)*2*pi*t);
cs=sin(440*(p^4)*2*pi*t);
d =sin(440*(p^5)*2*pi*t);
%ds=sin(440*(p^6)*2*pi*t);
e =sin(440*(p^7)*2*pi*t);
%f =sin(440*(p^8)*2*pi*t);
fs=sin(440*(p^9)*2*pi*t);
%g =sin(440*(p^10)*2*pi*t);
gs=sin(440*(p^11)*2*pi*t);

a2=sin(440*(p^12)*2*pi*t);  % a one octave up
a3=sin(440*(p^24)*2*pi*t);  % another octave up

clf;                                % clear the figure

subplot(5,1,1)
plot(t,a)
axis([0 0.05 -4 4])
title('A (440 Hz)');
ylabel('Speaker location');
xlabel('                                                                  Time (seconds)');
drawnow
sound([a a a a],44100)              % play the a four times in a row

wavwrite([a a a a],44100,16,'Pure_A_440_Hz');

%pause                              % press a key to continue

subplot(5,1,2)
plot(t,a2)
axis([0 0.05 -4 4])
title('A (880 Hz)');
drawnow
sound([a2 a2 a2 a2],44100)
%pause

wavwrite([a2 a2 a2 a2],44100,16,'Pure_A_880_Hz');

subplot(5,1,3)
i=(1:length(a3))/44100;
plot(t,a3.*i)
axis([0 0.05 -0.1 0.1])
title('A (1760 Hz) getting louder');
drawnow
i=(1:length(a3))/44100;
sound([a3.*i a3.*i a3.*i a3.*i],44100)
%pause

wavwrite([a3.*i a3.*i a3.*i a3.*i],44100,16,'Pure_A_1760_Hz_getting_louder');


subplot(5,1,4)
chord1 = a+cs+e;                      % superimpose the notes for a chord
chord1 = chord1/max(abs(chord1));
plot(t,chord1)
axis([0 0.05 -4 4])
title('A-C#-E chord (440, 554, 659 Hz)');
drawnow
sound([chord1 chord1 chord1 chord1], 44100) % play the chord
%pause

wavwrite([chord1 chord1 chord1 chord1],44100,16,'A_Cs_E_chord');

subplot(5,1,5)
chord2 = a+cs+e+3*a2;                   % broaden the chord
chord2 = chord2/max(abs(chord2));
plot(t,chord2)
axis([0 0.05 -6 6])
title('A-C#-E-A2 chord (440, 554, 659, 880 Hz)');
drawnow
sound([chord2 chord2 chord2 chord2], 44100)
wavwrite([chord2 chord2 chord2 chord2],44100,16,'A_Cs_E_A2_chord');

%clf;
scale=[a b cs d e fs gs a2];
sound(scale,44100) % play a little scale
wavwrite(scale,44100,16,'A_440_A_880_scale');

%pause

z =sin(20*2*pi*t);
wavwrite([z z z z],44100,16,'20_Hz');

z =sin(60*2*pi*t);
wavwrite([z z z z],44100,16,'60_Hz');

z =sin(80*2*pi*t);
wavwrite([z z z z],44100,16,'80_Hz');

z =sin(100*2*pi*t);
wavwrite([z z z z],44100,16,'100_Hz');

z =sin(120*2*pi*t);
wavwrite([z z z z],44100,16,'120_Hz');

z =sin(10000*2*pi*t);
wavwrite([z z z z],44100,16,'10000_Hz');

z =sin(16000*2*pi*t);
wavwrite([z z z z],44100,16,'16000_Hz');

z =sin(20000*2*pi*t);
wavwrite([z z z z],44100,16,'20000_Hz');