The name of this band in Camera Obscura, and the song is called "The Sweetest Thing". After watching this video, my only question is "Why don't I get invited to rock and roll costume parties like this?" The mustached lady is actually supposed to be Paul Simon, and then there's someone dressed like Art Garfunkel and there's someone else dressed like David Bowie and there are even people dressed like members of Fleetwood Mac.
I wouldn't necessarily put this song on at a party, but then again I tend to play really awful music at parties. This song is very pleasant on the ears, and I feel like if I heard it on a more regular basis then I would be much more cheery when hanging out and interacting with people. This song also makes me curious of what the rest of the album sounds like.