Even if you've never heard of auto-tune, you've heard it -- it's that slightly robot-like vocal processing effect that's used in every other pop song these days. Developed more than a decade ago as a studio tool to allow engineers to fine-tune the pitch of a singer's performance, it's become standard equipment. Time recently quoted an unnamed Grammy-winning recording engineer as saying, "Let's just say I've had Auto-Tune save vocals on everything from Britney Spears to Bollywood albums. And every singer now presumes that you'll just run their voice through the box." The same article expressed "hope that pop's fetish for uniform perfect pitch will fade," speculating that pop-music songs have become harder to differentiate from one another, as "track after track has perfect pitch."
A number of singers refuse to use auto-tune for reasons of artistic integrity. Death Cab for Cutie were recently seen wearing blue ribbons to protest its overuse in pop music, and singer Neko Case recently went on a mini-rant about it in Pitchfork:
When I hear auto tune on somebody's voice, I don't take them seriously. Or you hear somebody like Alicia Keys, who I know is pretty good, and you'll hear a little bit of auto tune and you're like, "You're too good for that. Why would you let them do that to you? Don't you know what that means?" It's not an effect like people try to say, it's for people like Shania Twain who can't sing. Yet there they are, all over the radio, spraying saccharine all over you. It's a horrible sound and it's like, "Shania, spend an extra hour in the studio and you'll hit the note and it'll sound fine. Just work on it, it's not like making a burger!"
You might not notice subtle adjustments in a performer's voice like a singer like Case does. But I'm certain you've noticed auto-tune used in the much less subtle way that's become super popular of late -- as an over-the-top voice effect which broke onto the scene with Cher's 1998 hit "I Believe" and has now become indelibly associated with T-Pain (here's a classic example). Thankfully, hopefully, auto-tune is starting to become passe -- the first sign of which are elaborate YouTube parodies of the technique. Here are a few of my favorite, by YouTuber schmoyoho.
Check out what auto-tune can do even to people who aren't singing -- like Newt Gingrich and Katie Couric -- and it becomes obvious how powerful a tool it is when used on the voices of people who are. (And doesn't it sound silly?)
Or, if you'd rather get historical up in this, here's Martin Luther King, Jr.'s famous "I Have A Dream" speech -- auto-tuned.