Michael Jackson Producer: Controversial Posthumous Songs Underwent 'More Processing'Just days before the first posthumous Michael Jackson album hits, controversy is still raging. A new UK Reuters interview with Teddy Riley, one of the "main producers" on 'Michael,' reveals that the vocal material culled for the album was far from finished.

"I had to do more processing to the voice, which is why people were asking about the authenticity," Riley says. "We had to do what we had to do to make ... his voice work with the actual music."

The album is set for release Dec. 14. Of the batch of recordings used for 'Michael,' Riley, who worked with Jackson before his death, says MJ would "never consider it being a final vocal."

"But because he's not with us he cannot give us new vocals. What we did was utilize the Melodyne (technology) to get him in key," Riley says. "With the Melodyne we actually move the stuff up, which is the reason why some of the vibrato sounds a little off or processed, over-processed. We truly apologize for that happening, but you are still hearing the true Michael Jackson."