It's impossible to calculate Timbaland's impact on urban music. Beginning in the mid-'90s, the Virginia producer not only revolutionized how hip-hop and R&B sounded, he also changed how pop audiences view the role of the producer. His work for Missy Elliott and Aaliyah elevated those figures into the spotlight, and introduced a singular production aesthetic that incorporated tabla rhythms and electro flourishes. The sound was witty and eclectic, and the five albums he created with Missy Elliott -- from 1997's Supa Dupa Fly to 2003's This is Not a Test -- are among Southern hip-hop's most treasured. They were immediate and visceral, alternately giant and quirky, building bombast out of world music nuances. You can hear Timbaland's influence in nearly every Southern and Midwestern producer, and his sound has been adopted by pop acts ranging from Justin Timberlake to Nelly Furtado. He is among the most respected figures in hip-hop, and in many ways is comparable to legendary pop producers such as Phil Spector.