You've been hearing it for more than 20 years, even before Cher released "Do You Believe in Love," though you may not realize it. Antares Auto-Tune is an audio manipulation program that allows a user to change the pitch (another way of saying "tune") of any sound. It started out life as a tool to make audio production easier and faster. And for folks doing home music recording, it was the holy grail.
Auto-Tune is a brand name, but the effect it produces is becoming so wide-spread that it's getting to be a generic term for pitch-correction software tools. Probably its biggest competitor is Celemony Melodyne .
They all do pretty much the same thing; namely, move out-of-tune musical notes to where they were supposed to be. For example, if a singer recorded a song, and had a few out-of-tune places, the audio engineer can fix it electronically.
OK, so what's the big deal? Aha! I knew you'd ask that. Well it turns out that some folks think using Auto-Tune is "cheating." Those folks may say things like "but the singer didn't actually HIT the notes! The computer did it for him." Technically, that is true. But there are other factors to be considered here.
First off, when someone is recording music to be played back (hopefully) many times by lots of the same people, I think the producer has a responsibility to put out an excellent, in-tune product.
Secondly, the recorded music you've been hearing for the last 30 years or so is rarely (VERY rarely) a recording of a musician doing a single take. It is common practice to have the singer perform the entire song at least three times so the producer can create a single "composite" performance using the best parts of all the versions. Heck, every movie you've ever seen is made this way. Does it somehow diminish the skill of an actor in your eyes knowing that he did several takes of a scene?
So the question becomes "if the singer didn't hit all the notes in one single performance on a recording anyway, why should it matter which editing method was used if the final product sounds great?" My answer is, "it doesn't matter at all."
Whoa, some of you are grinding your teeth a little bit. Okay then, let me add some factoids to what I've already said. Auto-Tune can, and most often is, over-used.
It is possible to wash every single note a singer sings through Auto-Tune, which frequently makes the voice sound less human to me. It isn't natural sounding if you do that. When I talked about the final product sounding great, I meant it should NOT sound like a machine sang the song! My preferred method is to touch up just the notes that are out of tune, and not even all of those!
I also think a singer should be able to "bring it" when performing live. They make Auto-Tune for live performance, but that is closer to where I draw the line between a real and a "fake" performance. There are a lot of singers out there on the radio who are very....average...and would never be able to make it on their live singing alone. And that does rub me the wrong way.
Auto-Tune was hailed as a "holy grail" for music producers because it is much faster than the compositing process I mentioned earlier. Another reason is that a singer can relax more when recording because they know certain things can be adjusted after-the-fact. Ironically, a relaxed singer yields a better performance to start with! Studio singing can be really nerve-wracking.
So my verdict on the whole Auto-Tune thing is that when used sparingly, and mostly on recordings, it is a powerful and wonderful tool. But like anything powerful, too much of a good thing can be extremely bad. Use it wisely.