The following code is what composes the .m file that satisfies this homework assignment. The first part (labeled "Part 1") plays the first line of 'Smoke on the Water' by Deep Purple, then plays it at 2x speed, then 2x amplitude. The second part load the Beatles song, plays it, then reverses it, and plays it again. The source code below is attached, as well as the .wav file of the reversed beatles song. I am not certain what it says in revers, but I have to believe that whatever the random collection of notes is that would be produced by playing it in reverse would not be intentional, or even particularly legible.
%Derek Richards
%HW 1 ECE 301
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b=(112/60); %b is the time of one standard beat
half_b=0.5*(112/60);
delta=0.000025; %arbitray variable small enough to sample well
w=@(tempo)0:delta:tempo; %whole note
h=@(tempo)0:delta:0.5*tempo; %half note
q=@(tempo)0:delta:0.25*tempo; %quarter note
dotq=@(tempo)0:delta:1.5*0.25*tempo; %dotted quarter note
e=@(tempo)0:delta:0.125*tempo; %eigth note
A4=440; %Frequency of note A4
%Note funtion takes 2 variables
%ntype: type of note (w,h,q,dotq,e)
%dev_A4: deviation from note A4 positive is up the scale, negative is down
NOTE = @(ntype,dev_A4) sin(2*pi*2^(dev_A4/12)*A4*ntype);
%Smoke on the Water, by Deep Purple
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(dotq(b),4),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(e(b),5),1/delta);
sound(NOTE(h(b),4),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(dotq(b),4),1/delta);
sound(NOTE(e(b),1),1/delta);
sound(NOTE(e(b),1),1/delta);
sound(NOTE(h(b),-2),1/delta);
%Silence to create a pause before 2x speed
sound(NOTE(q(8),68),1/delta);
%Smoke on the Water, by deep Purple, twice tempo
sound(NOTE(q(half_b),-2),1/delta);
sound(NOTE(q(half_b),1),1/delta);
sound(NOTE(dotq(half_b),4),1/delta);
sound(NOTE(q(half_b),-2),1/delta);
sound(NOTE(q(half_b),-2),1/delta);
sound(NOTE(q(half_b),1),1/delta);
sound(NOTE(e(half_b),5),1/delta);
sound(NOTE(h(half_b),4),1/delta);
sound(NOTE(q(half_b),-2),1/delta);
sound(NOTE(q(half_b),1),1/delta);
sound(NOTE(dotq(half_b),4),1/delta);
sound(NOTE(e(half_b),1),1/delta);
sound(NOTE(e(half_b),1),1/delta);
sound(NOTE(h(half_b),-2),1/delta);
%Silence to create a pause before x(2*t) speed
sound(NOTE(q(8),68),1/delta);
%Smoke on the Water, by deep Purple, x(2*t)
NOTE = @(ntype,dev_A4) sin(2*2*pi*2^(dev_A4/12)*A4*ntype);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(dotq(b),4),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(e(b),5),1/delta);
sound(NOTE(h(b),4),1/delta);
sound(NOTE(q(b),-2),1/delta);
sound(NOTE(q(b),1),1/delta);
sound(NOTE(dotq(b),4),1/delta);
sound(NOTE(e(b),1),1/delta);
sound(NOTE(e(b),1),1/delta);
sound(NOTE(h(b),-2),1/delta);
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%lets assume the file Beatles.wav is in the current directory...
[beatle_song, Fs] = wavread('Beatles.wav');
sound(beatle_song,Fs);
beatle_song_rev = flipud(beatle_song);
sound(beatle_song_rev,Fs);
wavwrite(beatle_song_rev,Fs,'Ece301_HW1_part2');
%END CODE
Beatles Song: Media:Ece301_HW1_part2_Derek_Richards.wav
