This is a cover of Tightrope performed by Karmin.
This is an a cappella cover of We Are Young by Pentatonix.
Little Mix (formerly known as Rhythmix) were contestants on The X-Factor in 2011.
So, I’m searching around YouTube looking for covers and I come across an ad that says “Best Cover singer? – Patrick Lentz has become a Youtube sensation.” Is he the best cover singer? Probably not, but this song is pretty good.