Antares Auto-Tune Evo 6 Full version is a multi-platform plug-in that  corrects intonation problems in vocals or solo instruments, in real  time, without distortion or artifacts, while preserving all of the  expressive nuance of the original performance with audio quality so  pristine that the only difference between what goes in and what comes  out is the intonation. Over a typical pitch correction range, it is  simply not possible to tell that a sound has been processed, except that  it is perfectly in tune. 

Most common  pitch problems can be corrected by Auto-Tune 4's Automatic Mode.  Automatic Mode instantaneously detects the pitch of the input,  identifies the closest pitch in a user-specified scale (including minor,  major, chromatic and 26 historical and microtonal scales), and corrects  the input pitch to match the scale pitch. A Retune Speed control lets  you match the retune rate to virtually any performance style. 

For  meticulous tweaking, the Graphical Mode displays the performance's  detected pitch envelope and allows you to draw in the desired pitch  using a variety of graphics tools. This mode gives complete control over  the correction or modification of the most elaborate expressive  gestures.