Two Can Keep a Secret

I was watching Gossip Girl episodes from Season 1 recently and stumbled across a clip where two beautiful ladies were singing a song. Their sound immediately struck me, so I followed up with some serious Wikipedia and YouTube research. Both led me to discover this live performance of "Secret" by The Pierces:

Absolutely wonderful. Glamorous, fabulous, delicious and everything else at once (I still have to come up with my own definitions of glamorous, fabulous and the difference between the two). What struck me in this performance:

1. The visual contrast between the two singers (who are sisters, by the way). The blond plus brunette is the oldest trick in the book, but there is a good reason for it. It is just so visually pleasing to see the juxtaposition that you cannot keep your eyes off them. It also does not hurt that they both have gorgeous figures.

2. The blonde's voice and facial expressions. The voice is absolutely gorgeous. It is crisp, melodious and pretty strong. Perfect for this song. Her eyes and lips are also very expressive throughout the performance. She is not afraid to get her hands (face?) dirty and make grimaces that would better convey the message. Of creepiness and impending murder. See next point.

3. The creepy lyrics and way of singing. Creepy AND sensual. I feel like this could be a lost scene from Chicago and either one of them is about to kill the other...or me. Creepy and erotic. As per the discussion of terror being glamorous on DeepGlamour, the terror here arises from the threat of murder because of a broken word to keep a secret. Terror/glamour/eroticism image is completed by the monotonous dance.

This is the original Gossip Girl clip: