Producer: P. Diddy, Mario Winans

When Faith Evans and Carl Thomas got in the studio together in 2001, the duo composed a song that would show off both of their unique vocal styles; the result was "Can't Believe." The record was produced by Mario Winans and P. Diddy, who used a sample from The Firm's single "Phone Tap." The Firm, once considered a hip hop supergroup because of its absurdly-talented membership (Nas, Foxy Brown, AZ, and Nature) released a record that was widely considered a flop. But Carl and Faith were able to flip the "Phone Tap" string and bass driven beat in way the complimented both of their vocals perfectly and allowed Carl Thomas to harmonize with the guitar section. —Tannis Spencer

Inspiration: The Firm f/ Dr. Dre "Phone Tap" (1997)

Producer: Dr. Dre, Chris "The Glove" Taylor