Procurar *.mp3 em todo o HD

CODE  
procedure CreateFileList(var List : TStringList; Dir, Mask : string);
var
 SearchRec: TSearchRec;
begin
 try
   IncludeTrailingPathDelimiter(Dir);
   if FindFirst(Dir + Mask, faAnyFile, SearchRec) <> 0 then
   begin
     FindClose(SearchRec);
     Exit;
   end;
   List.Add(searchrec.name);
   while FindNext(SearchRec) = 0 do
    List.Add(SearchRec.name);
 finally
   FindClose(SearchRec);
 end;
end;