% Program song1a.m
% Prepared by S. Scott Moor, IPFW  August 2004
% Based on suggestions from Shreekanth Mandayam, 
%   Department of Electrical and Computer  Engineering, Rowan University, 
%    see http://users.rowan.edu/~shreek/networks1/music.html
%
% To play song simply type “song1a” at the command line 
% this file must be in the current directory or on the MATLAB path
%
% This program creates sine waves for a series of standard
% notes.  Each note is set up to be 0.5 seconds long at a 
% sample rate of 8000 Hz.  The notes are assembled into a 
% song that is then played by the computer speaker.

% variables used: 
%	sf	= sampling frequency (samples/sec)
%	x	= time vector (sec.)
%	a, b, cs, d, e, & fs = the amplitude series for the notes used in the song 
% 	line1, line2, line3 = the amplitude series for each line of the song
%	song 	= the amplitude series for the entire song. 

% set up time series
sf = 8000;
x = 0:1/sf:0.5;

% define each note
a=sin(2*pi*440*x);
b=sin(2*pi*493.88*x);
cs=sin(2*pi*554.37*x);
d=sin(2*pi*587.33*x);
e=sin(2*pi*659.26*x);
fs=sin(2*pi*739.99*x);

% assembling the notes into a song
line1 = [a,a,e,e,fs,fs,e,e];
line2 = [d,d,cs,cs,b,b,a,a];
line3 = [e,e,d,d,cs,cs,b,b];
song = [line1,line2,line3,line3,line1,line2];

% now we play the song
sound(song, sf)