We have a new #1 (and milestone) for Justin Bieber, who captures the first Number One pop song of his career with "What Do You Mean?". Congrats to Team Def Jam for the win! But trailing close behind him while going for her fifth chart topper from 1989 is this week's Greatest Gainer Taylor Swift, with "Wildest Dreams" (Big Machine/Republic). Another record with big momentum inside the Top 10 is One Direction's "Drag Me Down" (SYCO/Columbia) which moves to #7. Macklemore & Ryan Lewis' "Downtown" (Macklemore/Warner Bros.) is sitting just outside the Top 10 and looking to crack it. Drake's "Hotline Bling" (YMCMB/Republic) moves Top 15. Charting this week will be 5 Seconds of Summer's "Hey Everybody!"(Capitol).