This is a Korean pop girl group that's been pretty big in Korea lately (you've been warned beforehand that it's a pop group). Unlike many pop girl groups out there, they actually sing really well live as most of the members had experience in the music industry before being scouted for SNSD.
Their latest MV:
[video]http://www.youtube.com/watch?v=-LN6rtpU7E4[/video]
And then a performance/appearance that five of the girls did on Music Travel LaLaLa (4 parts):
SNSD singing 2 songs, a talk, and at 8:20 Tiffany sings Mariah Carey's Hero a capella:
[video]http://www.youtube.com/watch?v=EApasdpkGnk[/video]
SNSD covering two songs, the last one being Super Junior (their male counterpart)'s song:
[video]http://www.youtube.com/watch?v=My4_djGH24E[/video]
A talk, and at 3:05 of this is a duet (Falling Slowly by Glen Hansard) with Sunny from SNSD and a guy from Super Junior:
[video]http://www.youtube.com/watch?v=7lulRip04fo[/video]
Really pretty quartet with Jessica (short bobbed hair) and Taeyeon (first one to sing) from SNSD and two Super Junior dudes:
[video]http://www.youtube.com/watch?v=g_xKyqyznp8[/video]
All I really have to say is that they have amazingly sexy legs and wonderful voices. Definitely sexy legs.