julia nunes
https://www.youtube.com/watch?v=I8K54UYjIR4&list=PL96EAC4022650DA78
walk off the earth - royals
https://www.youtube.com/watch?v=QgD5p1XiVT0
trombone sample happy
https://www.youtube.com/watch?v=ZxODzxY6AvI
virtual choir 2000 voices
http://www.ted.com/talks/eric_whitacre_a_virtual_choir_2_000_voices_strong