Reading File Structure

Whenever I attempt to read a tag from an mp3 file on CD I get an "file
access denied". I know that files on CD are readonly. I need only to read
the ID3 tag of the mp3 file. Any other ways to accomplish this?

Here is the code that I use:


function GetID3Tag(aSong: TFileName): Boolean;
var
  f: file;
  error: integer;
begin
  AssignFile(f, aSong);
  {$I-} reset(f, 1); {$I+} // produces "file access denied" on CD files but
ok with fixed drives.
  error := IOResult;
  if error = 0 then begin
    Seek(f, FileSize(f) - 128);
    BlockRead(f, ID3Tag, SizeOf(ID3Tag));
    CloseFile(f);

    Result := ID3Tag.Header = 'TAG';
  end else Result := false;
end;