We have a new #1 at T40 this week, as Charlie Puth's "Attention" (Atlantic) climbs to the top of the chart. The current Greatest Gainer is Justin Bieber & BloodPop's "Friends" (GPOP/RBMG/SB/Def Jam/Republic) as it impacts the format and climbs up inside the Top 20, but watch out because here comes the newly-released Taylor Swift, "Look What You Made Me Do" (Big Machine/Republic). In just a few hours within release it had immediately charted and is promptly heading Top 25. Meanwhile, P!NK's "What About Us" (RCA) is poised to join the Top 20. Also charting this week will be Halsey's "Bad At Love" (Astralwerks/Capitol) and Why Don't We's "Something Different" (SignatureEnt/Atlantic).