Pentatonix (often abbreviated as PTX) is an American a cappella group of five vocalists originating from Arlington, Texas.^[3] Their work, mostly into but not limited to the pop music style, consists of covers of pre-existing songs and some original material, sometimes in the form of medleys: their music is defined by their own arrangement style, a strong presence of low bass vocals, and a diverse range of vocal percussions.

Pentatonix formed in 2011 and came to prominence the same year by winning the third season of The Sing-Off on NBC, their victory earning them $200,000 and a recording contract with Sony.^[4][5] Their debut EP PTX, Volume 1 was released the following year, followed by PTXmas the same year, with their third release, PTX, Vol. II, debuting number 1 on the Independent Albums section of the Billboard 200 in 2013. 2014 saw the release of PTX, Vol. III, and their two first full-length albums, PTX, Vols. 1 & 2 (a compilation of Vol. 1 and Vol. II) and That's Christmas to Me. They have sold over 500,000 records.^[1] The group's third album PTX, Vol. III was released on September 23, 2014, which was followed by a Christmas album on October 21.