R. Kelly's collaboration with Lady Gaga on 'Do What U Want' and the release of 'Black Panties' has revitalized him in the mainstream eye. Funkmaster Flex isn't a fan of the new Kellz though.

The Hot 97 DJ and the singer had some low-key, personal beef prior to his scheduled appearance on the radio station earlier this week. When R. Kelly decided not to show up for his interview, the tension exploded in the form of a typical Funkmaster Flex rant.

Before the rant, Flex promoted what he was about to say on Twitter -- the tweet has been deleted. "I got choice words for R. Kelly tonight at 7pm!!!!!" he wrote. Flex was nothing short of irate when he showed up to 'The Angie Martinez Show' to express himself.

"Not that we care. Not that it's needed. That's what he needs. We don't care," Flex yelled. The New York DJ would not calm down throughout the five-and-a-half-minutes he spoke. Flex had to be constantly cut from the mic as Program Director Ebro Darden is repeatedly heard telling him to calm down.

The admonitions seemed to have the opposite effect, however. By the end of the discussion, Flex was in a full rage. "Now you think you're getting a little hot and you're not ... In a wack Lady Gaga ...," Flex's mic was completely cut before he finished his rant. Darden told Martinez to wrap because "this dude is wildin'."

This isn't the first time R. Kelly was the target of a Funkmaster Flex diss. The veteran R&B entertainer was one of the many targets of his New Year's Eve 2009 Twitter ethering session, in which he took aim at a number of artists. “What about R.Kelly dropping that brick album. ‘Mr. touchy feely’ -- crazy that this is allowed …,” he tweeted.

R. Kelly had released his 'Untitled' album a month prior.

In related news, the crooner felt a wave of negativity this week when promoting the 'Black Panties' album. Kelly created the hashtag '#AskRKelly' on Twitter and urged fans to ask him questions. Instead of staying on topic and providing questions about his music, fans and critics had a free-for-all.

From addressing his choice in clothing to a video that surfaced allegedly showing Kelly engaging in sex with, and urinating on an underage girl, nothing was off limits. “What it feel like to pee on somebody? …im asking for a friend. #AskRKelly,” asked one fan. Check out more of the wild questions here.

Listen to Funkmaster Flex's Hot 97 Rant Against R. Kelly