This video was brought to my attention by a co-worker and it blew me away.  With just their voices they sing you a run down of Beyonces songs in order of their release, or as they call it, the Evolution of Beyonce,Pentatonix is a group of 5 extremely talented instrument free musicians who won Season 3 of NBC's The Sing Off.  In this video they sing a bit of each song, making seamless transitions between each, making one incredible Evolution of Beyonce's songs.

Watch Evolution of Beyonce by Pentatonix

For more Pentatonix check out their website or Facebook and look for their Christmas EP 'PTXmas' due out November 13th.