Bop to the top. A cappella group Pentatonix, which includes cellist and beatboxer Kevin Olusola ’12, topped the Billboard 200 chart yesterday with its new self-titled album. The new record, released on Oct. 16, is the group’s first set composed of all original content. The singing group beat out Demi Lovato, who holds the No. 2 spot with her album “Confident.”