T-Pain remembers that an interaction he had with another music star, Usher, was the moment he began questioning himself.

“Usher was my friend. I really respect Usher,” T-Pain explains in an episode of the new, eight-part Netflix doc, This Is Pop. “And he said, ‘I’m gonna tell you something, man. You kinda f***ed up music.'”

The comment was a reference to T-Pain’s frequent use of Auto-Tune, an effect music producers began using in the late ’90s to alter voices. He became strongly associated with the effect in the mid- to late aughts, with songs such as “Buy U a Drank (Shawty Snappin’),” “Blame It” and “Low.”

But it had been used earlier: Cher’s “Believe” is full of it, and T-Pain first heard it on a remix of Jennifer Lopez’s song “If You Had My Love.” The man born Faheem Rasheed Najm became mesmerized instantly. And he — correctly, as it turned out — thought it could help set him apart from the many other aspiring rappers out there.