我在遍一个音乐程序，运行出现了：Division by zero,但我程序中并没有0作除数啊
这个是单元
unit music;
    interface
   uses crt;
    procedure play (octave,note,duration:integer);
    implementation
     procedure play;
      const
       base=32.625;
      var
       x:real;
       i:integer;
       begin
       if note=0 then delay(duration)
                 else begin
                   x:=base;
                   for i:=1 to octave do
                     x:=x+2;
                   for i:=1 to note-1 do
                   x:=x*1.059463994;
                sound(round(x));
                delay(duration);
            nosound;
                 end;
           end;
end.

这个是程序
program musicprogram (songfile);
uses music;
var
   songfile:text;
   octave,note,duration:integer;
begin
   assign(songfile,'song1.dat');
   reset(songfile);
   while not eof(songfile) do
   begin
    readln(songfile,octave,note,duration);
    play(octave,note,duration);
   end;
   close(songfile);
end.
请教一下