Possible Clues:

• Dr. who founded the Aftermath label
• Dr. featured in 2015's 'Straight Outta Compton'
• Beats Electronics cofounder, to fans
• N.W.A. cofounder, familiarly
• Eminem's 'Forget About ___'
• Friend of Eminem
• Dr. who's done 19-Down for Dr Pepper
• Dr. with a beat
• 'Forgot About ___' (1999 rap song)
• Dr. ___ (rapper)