In addition to refuting the statements made by members of the Jackson family and will.i.am, producer Teddy Riley says Michael Jackson’s producers hired three forensic musicologists in to prove his final album was authentic. Riley, who had previously worked with Jackson, Jay-Z, Dr. Dre and Big Daddy Kane, enlisted an eclectic group of fellow Jackson fans to complete the album, Michael. Names such as 50 Cent, Akon and Lenny Kravitz stand out among the album’s liner notes. But most of the contributors say, before his death, they were contacted by Jackson himself for the collaborations.

“I know he stood behind it, so I’m cool with what I did,” Kravitz told the Associated Press. “I was proud to put it out and knew that he’d be all over it, that he’d be really with it.”

Similarly, 50 Cent said he had a phone conversation with Jackson after DJ Whoo Kid met the King of Pop. Riley added that Jackson had already sectioned a portion of the song off for 50 while he was writing it.

Some songs, such as “Much Too Soon” were written during the ‘80’s, when Thriller was released. Others, like, “Hold My Hand,” were contributed by different artists.

“[‘Hold My Hand’] was pretty much finished, but his delivery creates a whole other environment—his tone and energy just made that record seem completely different,” Akon told Billboard. “We decided we would make it his record featuring myself, because I felt like he’d give it more mileage, and the record would be so, so much bigger if it was a Michael Jackson record.”

When discussing “Monster,” 50 Cent said the collaboration made him nervous. Stewart agreed, saying, “It was a tremendous amount of pressure because Michael was one of the great record-makers in the history of music. Not only are you trying to make sure that you’re keeping the integrity of the record, but you’re also trying to live up to the body of work.”

Even within the camp of contributors, opinions are split. Riley called the work a masterpiece. Meanwhile, Akon advised fans to look at the album differently.

“This is not like a finished product that you can compare anything to,” he explained. “It’s more of an album that you can hold onto to commemorate and appreciate his legacy.”