A new celebrity Twitter feud is brewing between rocker Steven Tyler and his American Idol replacement Nicki Minaj after the ex-judge took aim at the new panellist and suggested she wouldn't be able to spot true talent on the show.

The Aerosmith rocker told his fans that new judges Mariah Carey and Minaj should try to get along for the benefit of the "scared" wannabes auditioning for them.

Commenting on the divas' recent on-camera fight over a contestant, he tweeted, "I know that they've got something going on on the judges' panel; it shouldn't be that, it should be the opposite. They should have something going on, which is called 'camaraderie'.

"These kids, they just got out of a car from the Midwest somewhere and they're in New York City, they're scared to death; you're not going to get the best (from them)."

He went on to suggest that Minaj, in particular, would not be able to spot the next great troubadour if he showed up on stage in front of her, adding, "If it was Bob Dylan, Nicki Minaj would have had him sent to the cornfield. Whereas, if it was Bob Dylan with us, we would have brought the best of him out."

Minaj, Carey and fellow new judge Keith Urban were drafted in to replace Tyler and Jennifer Lopez when they quit the show this summer (12), and the Starships hitmaker is refusing to take the rocker's criticisms lying down.

In a series of angry tweets on Monday (26Nov12), she raged, "Steven Tyler said I would have sent Bob Dylan to a cornfield??? Steven, you haven't seen me judge one single solitary contestant yet! You assume that I wouldn't have liked Bob Dylan??? Why? Black? Rapper? What? Go f**k yourself and worry about yourself babe.

"I understand you really wanted to keep your job, but take that up with the producers. I haven't done anything to you. That's a racist comment.

"When Steven first went on Idol he was ridiculed by his peers and fans alike. Called a sell out. So what does he do? Ridicule the next judge."