Antares autotune pitch correction software can undetectably correct bad pitching and has been about for years it is practically an industry standard now.Many acts now use hardware versions of autotune at their live events.

Melodyne another audio editing prog can add or reduce vibrato and change the formants of your voice from male to female or vice versa or change a bass voice to a soprano or alter the tempo or rhythm of a sung or played phrase without affecting the pitch,incredible software from Germany that's been about for a couple of years it costs about £600 autotune costs about £300 and can be used as an audio plugin for the likes of Cubase or Logic Audio.

Most of the pretty faces and even old established names are using these tools to turn in what they imagine are "perfect" performances.I much prefer the natural sound and the slight imperfections that come with it.