Pentatonix (often abbreviated as PTX) is an American a cappella group of five vocalists originating from Arlington, Texas. The members are Scott Hoying (baritone lead/harmony), Kirstie Maldonado (mezzo-soprano lead/harmony), Mitch Grassi (counter-tenor leadharmony), Kevin Olusola (percussion), and Avi Kaplan (bass).

Their work, mostly in, 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 percussion.

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. Their debut EP "PTX, Volume 1" was released in 2012, followed by "PTXmas" the same year, with their third release "PTX, Vol.

II", debuting at number 1 on Billboard's Independent Albums chart 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".Pentatonix started their popular YouTube channel back in 2012 to promote themselves after the Sing-Off (Season 3, 2011) when they were dropped by their record label, according to a recent November 2014 interview.

They also made effective use of social media to interact with their fan base. Having eclipsed 6.99 million subscribers and more than 714 million cumulative views, the PTXofficial YouTube page is currently the 12th most subscribed-to music channel (as of 12 December 2014).

Their music video for "Daft Punk" recently surpassed 106 million views.The group's website is: www.ptxofficial.com. Pentatonix official youtube channel: www.youtube.com/PTXofficial.