HW1.1 Dan Morris ECE301Fall2008mboutin - Rhea

%Dan Morris %drmorris@purdue.edu %EE 301 Hw1.1

clear;clc; %define sampling rate as 20 kHz delta=1/20000;

%now define the duration of each note, take quater note (q) to be 172 bpm. q=60/172;  %quater h=2*q;  %half w=4*q;  %whole e=q/2;  %eighth dotq=3/2*q;  %dotted quater doth=3*q;  %dotted half

%now define the note frequencies x=3/5*440;  %(440=5x/3 => x=3*440/5 => x=264) A=5/3*x; B=15/8*x; C=x; D=9*x/8; Db= 277.18; E=5/4*x; F=4/3*x; G=3/2*x; Gb= 369.99;

%now to define the song using arrays notes=[A,B,Db,D,E,Gb,Gb,G,G,G,D,E,F,Gb]; duration=[h,q,q,dotq,e,q,q,q,e,e,q,e,e,doth];

%A) now to play the song at normal speed for n=1:length(notes)

   time=1:delta:duration(i);
   song=sin(2*pi*notes(i)*time);
   sound(song, 1/delta);

end

pause(3)

%B) now to play the song at twice as fast for n=1:length(notes)

   time=1:delta:0.5*duration(i);
   song=sin(2*pi*notes(i)*time);
   sound(song, 1/delta);

end

pause(3)

%C) now play the song x(t) scaled to y(t) = x(2t) for n=1:length(notes)

   time=1:delta:duration(i);
   song=sin(2*2*pi*notes(i)*time);
   sound(song, 1/delta);

end