Mariah Carey says working with Pharrell Williams was ''a real collaborative moment''.

The 50-year-old songstress teamed up with Pharrell for her 10th album, 'The Emancipation of Mimi', which celebrates its 15th anniversary this month, and Mariah admitted she broke her own rules of doing her vocals alone to work closely with Pharrell on the track 'Say Something'.

She explained to Billboard: ''Those writing sessions were great. Pharrell is just such a vibrant person and artist, so I really enjoyed making that record with him and collaborating with Snoop [Dogg] again on that song. It wasn't my usual session, because I did the vocals there with [Pharrell] in the studio. Usually I go in by myself and just do whatever I'm feeling, but it was a real collaborative moment.

''[The label] wanted to actually go with 'Say Somethin' as the lead single. [They] were like, 'I love it, I love it. It's so different for you. You should go with it.' I felt like it was a really strong album cut, but I didn't see it as the first single for me, because I thought it was too different. I think we really made the right choice artistically to work [with Pharrell]. It was such a perfect time in my life and my career for that.''

And 15 years later, Mariah is still hugely proud of the album.

She said: ''It really was a moment and it did feel special. When I think about all the different songs on [the album] and the different collaborators, the timing was just right. It was the first time I collaborated with The Neptunes [Pharrell and his producing partner Chad Hugo], and it was the first time I worked with [the late James] 'Big Jim' Wright as a producer with 'Circles' and with 'Fly Like a Bird'.''