T-Pain Just Sang Without Auto-Tune, and His Voice May Surprise You This is T-Pain singing like you've never heard him before.

 -- In the mid-2000s, while Jay-Z was still officially in retirement and long before Kanye West had been reborn as Yeezus, a guy named T-Pain stepped into popular hip-hop's post-"Crunk" era and briefly changed how hits were made.

T-Pain wasn't the first to use Auto-Tune, the pitch-modification effect, in his music. But he was the first to use it to twist and braid his voice into a brand new musical instrument for pop music. Soon enough, he was basically synonymous with the effect.

He was featured on tracks by superstars such as Kanye, R. Kelly, and Jamie Foxx. Diddy reportedly gave him royalties just for using Auto-Tune on a record, and an iPhone app called "I Am T-Pain" let users simulate Auto-Tune effects on their own.

'GMA' Auto-Tune: Songs of Summer

Neil Patrick Harris Tackles the Tonys; New Mr. Rogers Auto-Tune

But sometime after Jay-Z’s 2009 hit “D.O.A. (Death of Auto-Tune)” and T-Pain’s hilarious appearance on “I’m on a Boat” by comedian Andy Samberg and his band The Lonely Island, T-Pain started to become the joke. The number of musicians and critics who condemned Auto-Tune as a crutch was hitting a critical mass. And many of them were calling T-Pain a one-trick pony who hid behind Auto-Tune to make up for his own shortcomings as an artist.

But T-Pain, born Faheem Rasheed Najm, may have just silenced many of those critics with a stunning unplugged performance on NPR’s Tiny Desk Concerts series.

In the video, he’s traded in the top hat and over-sized shades of his heyday for clear glasses and a black baseball cap, and a keyboard synth is his only company. In the intimacy of the Tiny Desk set, T-Pain lets loose without a trace of Auto-Tune.

“This is weird as hell for me,” he jokes in the video. “I've never done anything like this.”

Audiences have never heard T-Pain like this before. As he belts out his first No. 1 single, “Buy U a Drank,” along with two singles from an upcoming album, T-Pain’s uncooked vocals leap out at the listener. The soft synth tones behind him turn the whole set into a music box. And T-Pain, he of the robotic Auto-Tune voice, has never sounded more human.

The decision to do the concert, T-Pain said, was pretty impromptu. "I didn't really plan to do this at all," T-Pain told ABC News. "But I did it because I knew I could do it."

Recording and performing more unplugged songs is something T-Pain said he's interested in for the future. In the shorter term, he mentioned his interest in recording some of his greatest hits as unplugged, pared-down songs featuring his natural voice. That's an idea that his labels have never seemed enthusiastic about, he said. "I think they didn't want to do it because they didn't know I could do it," he told ABC News. "I think they'll do it now."

Even as he gets ready to showcase his raw vocals more in the future, though, he said he's not interested in getting rid of the Auto-Tune for good. "I'm keeping it, man," he said. "That's what made me. As long as people know what I can do without it."

Listen to T-Pain unplugged below on NPR’s Tiny Desk Concerts series: