HW1 ECE301S11 Hale Petersen - Rhea

% Hale Petersen
% ECE 301 HW # 1

clc

% Q.1 - Part 1: original tempo
BPM = 112; % beats per minute
BPS = 60/BPM; % beats per second
delta = 0.00005;
Q = [0:delta:BPS];
E = [0:delta:BPS/2];
DQ = [0:delta:BPS*1.5];
H = [0:delta:BPS*2];

%Notes
Q_G = sin(2*pi*(2^(-2/12)*440)*Q);
Q_BF = sin(2*pi*(2^(1/12)*440)*Q);
DQ_C = sin(2*pi*(2^(3/12)*440)*DQ);
E_DF = sin(2*pi*(2^(4/12)*440)*E);
H_C = sin(2*pi*(2^(3/12)*440)*H);

song1 = [Q_G, Q_BF, DQ_C, Q_G, Q_BF, E_DF, H_C, Q_G, Q_BF, DQ_C, Q_BF, Q_G];
sound(song1, 1/delta);
pause(10);

% Part 2: 2 times faster by dividing the BPS by 2
Q = [0:delta:BPS/2];
E = [0:delta:BPS/4];
DQ = [0:delta:BPS*1.5/2];
H = [0:delta:BPS];

%Notes
Q_G = sin(2*pi*(2^(-2/12)*440)*Q);
Q_BF = sin(2*pi*(2^(1/12)*440)*Q);
DQ_C = sin(2*pi*(2^(3/12)*440)*DQ);
E_DF = sin(2*pi*(2^(4/12)*440)*E);
H_C = sin(2*pi*(2^(3/12)*440)*H);

song2 = [Q_G, Q_BF, DQ_C, Q_G, Q_BF, E_DF, H_C, Q_G, Q_BF, DQ_C, Q_BF, Q_G];
sound(song2, 1/delta);
pause(10);

% part 3: rescaling by doubling the frequency to 880
Q = [0:delta:BPS];
E = [0:delta:BPS/2];
DQ = [0:delta:BPS*1.5];
H = [0:delta:BPS*2]; 

%Notes
Q_G = sin(2*pi*(2^(-2/12)*880)*Q);
Q_BF = sin(2*pi*(2^(1/12)*880)*Q);
DQ_C = sin(2*pi*(2^(3/12)*880)*DQ);
E_DF = sin(2*pi*(2^(4/12)*880)*E);
H_C = sin(2*pi*(2^(3/12)*880)*H); 

song3 = [Q_G, Q_BF, DQ_C, Q_G, Q_BF, E_DF, H_C, Q_G, Q_BF, DQ_C, Q_BF, Q_G];
sound(song3, 1/delta);
pause(10);

% Q.2 Hidden backward message
[beatles, Fs] = wavread('Beatles.wav');
beatles_reverse = flipud(beatles);
sound(beatles_reverse,Fs);

%Q.1 - The forward repeating phrase is "number nine"
%Q.2 - I believe the reverse says "turn me on dead man"