MTV adds

VIDDY THIS:  Fifth Harmony's "BO$$" (Syco/Epic) urges you took take a strut down the catwalk and snap your fingers in this celebration of confidence. Other winners in this week's round-up of MTV video adds include 5 Seconds of Summer's "Amnesia" (Capitol), Katy Perry's "This Is How We Do" (Capitol) and Iggy Azalea f/Rita Ora's "Black Widow" (Grand Hustle/Def Jam), which, as Iggy hinted today, "is coming sooner than you think." Stay tuned, y'all. (8/5p)