PPTX

MAKING NEWS WITH THEIR MOUTHS: When RCA's viral vocalists Pentatonix post a new clip, shit blows up. The a cappella troupe's latest, "La La Latch," is no exception, as the medley of Sam Smith-written and sung U.K. hits (credited to Naughty Boy and Disclosure, respectively) goes up on YouTube, garners about 70k views within hours and launches the track to #5 on the iTunes singles chart, while the group's EP, PTX, Vol. III, moves to #33 in pre-order. The seven-song set, which also features their versions of Ariana Grande's "Problem" and Stromae's "Papaoutai," among others, streets on 9/23. (9/2a)