Shirley Ju Cory Litwin is joining Neil Jacobson’s writer-producer management agency Hallwood Media as Executive Vice President and bringing with him Grammy-nominated hitmaker Murda Beatz (Drake’s “Nice For What,” Migos’ “Motorsport”) and the Murda Gang stable of more than a dozen producers and staff.Jacobson, the former president of Geffen Records, launched Hallwood earlier this year as an independent music management firm, publishing company and record label representing producers and