With a three-day holiday causing a number of stations to freeze, it was slower than usual this week for new music. The Most Added records were primarily close-outs from the superstar debuts we had last week.  In the top spot is Macklemore & Ryan Lewis' “Downtown” (Macklemore/Warner Bros.) tallying 14 more adds, followed by RBMG/Def Jam’s Justin Bieber, who pulled in 13 for “What Do You Mean?."  Avicii's “Pure Grinding” (PMRD/Island/Republic) and Calvin Harris' “How Deep Is Your Love” (Columbia) both nab 11 adds, while Drake's “Hotline Bling” (YMCMB/Republic) collects 8 new commitments.