By transforming the voice of its user, auto-tune transformed the face of rap. Even though Biz Markie and Ghostface had long since made off-key singing an integral part of the culture, auto-tune-which was invented for the express purpose of correcting the flaws in the human voice-actually enabled rap stars to make themselves stranger, less intelligible, and in many cases, more vulnerable.
It changed the course of Lil Wayne's career when he found a way to weep through auto-tune. Meanwhile, Kanye used the device to exorcise his grief in the wake his mother's death. Currently, guys like Future and Kevin Gates are using it to invent a whole new vocabulary for rap crooning. Jay-Z's "D.O.A." (later this year, "D.O.H.": "Death of Hyphenate") was the old guard's last-ditch attempt to hang onto rules that had already disintegrated.
Many saw the device as the bane of hip-hop culture; many more saw it as indefensibly annoying. All the better: transmutation is healthy for the culture, and if the changes bother people, that only means we're moving in the right direction. Besides, if you can't hear the deep blues in Future's "Turn On the Lights" you must be listening for the wrong reasons.