Hi Folks! I'm new around here, but would like to play. This is my favorite mash-up. All six singers are the amazing and largely un-discovered Sam Tsui and the brilliant young arranger and genius behind the multi-layer production is the beat-boxer on the left - Kurt Schneider. They've got a TON of outstanding work on both of their channels, if you get hooked like I did. 
Hope you enjoy!
Hope you enjoy!