Pentatonix is the eponymous fourth studio album by American a cappella group Pentatonix, to be released on October 16, 2015. The release date was announced on Twitter by a series of pictures featuring the five band members released over a five day-span, with one band member added to the picture each day, culminating in the date being revealed on August 28 2015. It is the band's seventh release. Pentatonix (or PTX) is an American a cappella group consisting of five vocalists originating from Arlington, Texas. The members in this group are Avi Kaplan, Scott Hoying, Kirstie Maldonado, Kevin Olusola, and Mitch Grassi. Their work, which is mostly in the pop style, consists of covers of existing songs, sometimes in the form of medleys, along with original material. Their music is defined by their own arrangement style, tight vocal harmonies, extensive vocal riffing, deep and steady vocal basslines, and a diverse range of vocal percussion and beatboxing.