Tomorrow marks the 20th anniversary of the release of Mary J. Blige's debut album, What's the 411?. No single disc of the past two decades did more to define the sound of R&B (though Aaliyah's One in a Million came close). The idea of singing straight R&B over hip-hop breaks (including classics like that of Audio Two's "Top Billin'," as heard in "Real Love") was a foreign concept at the time of its release. After 411? it become commonplace. Sometimes landmarks alter things so definitively that they end up subverting their own importance — 411? redefined sound so much that it's easy to forget just how revolutionary it once was. In today's context, it can sound like just a really tight collection of great songs.

Ebony has a terrific interview with 411? producers Dave "Jam" Hall and Cory Rooney, in which they describe engineering the revolution. Says Hall:

When Diddy [who did A&R for and helped produce 411?] was working on the project, he came to [manager] Eddie F. and I and said he was looking for this new type of sound for his artist. At that time, New Jack Swing was prominent and he told us that his artist wasn't New Jack Swing and that her style was a little bit grittier and a little more urban.

Back then, I was experimenting with putting hip-hop beats together with R&B chord progressions. I wasn't getting any traction with the sound because people didn't quite understand it. One day, I was in Eddie F.'s car in the backseat and Diddy was in the front and I played my tracks. He said, ‘That's exactly what I'm looking for! That's the new sound we need. This is new direction I need for this artist named Mary J. Blige.' This is how I became part of the project."

"Reminisce" was the disc's third single. It wasn't a huge pop hit, but was all over R&B radio and BET that fall. Says Rooney, who didn't produce it (Hall did):

I remember the day [Diddy] played ‘Reminisce' for us and we all said, ‘Damnit,'" he laughs. "We thought we had them and then he played us that record. He was dancing around the studio all hype.

Also excellent is the track's Pete Rock remix, which liberally samples his "They Reminisce Over You."

Happy 20, 411? R&B fans in 2012 would be lucky to get an album with a tenth of the pull that this had.