I disagree with the assessment that many people are making that Jessica lacked singing talent. She easily had the most powerful voice and widest tessitura of all the teen pop starlets from the late 90s/early 00s (she could go from E3 to Bb5 in full, connected voice). The problem is that she never received any formal training and lacked the intelligence to try to get it; eventually, her dismally bad technique utterly destroyed her vocal chords and what could have been a very promising career. She went from trying to belt to whispering and screaming, and eventually she lost all singing ability - however, instead of studying with a phoniatrician in order to recover her voice, she concentrated on reality TV and "designing" tacky crap, which will always be much easier.

Christina Aguilera has a much more beautiful and agile voice, but she barely manages to cover the tenor range before choking and straining. Anything higher than B4 is a challenge to her (which is downright insane for a "soprano"), and she screams, struggles and rasps her way through notes that are fairly easy for most females to sing. Also, her attempts to be "avant garde" have ruined her career, which at this point would need a miracle in order to return to what it once was.

Britney is an embarrassment and her delusional fans, deranged imbeciles. The proverbial "baby voice" that supposedly ruined her "real voice", never existed. She has always sounded like a chipmunk with a bad case of adenoidal enlargement, and there are no two ways about it. How this talentless slag managed to become a star, is one of the great mysteries of humanity.

As for Pink, she is definitely the dark horse of the bunch. She has more vocal talent than most people would have ever imagined, and she has proven to be intelligent enough to develop her voice. She has a huge range and much control, but I think that the fact that her voice isn't beautiful and she didn't sing standard balladry, made many people underestimate her. Still, she has basically been releasing the same record since 2006, so good for her on building a career on almost identical songs.

Regarding Beyoncé, she has worked extremely hard to develop what was a rather mediocre voice, and the results are stunning. She is the best singer of this group BY FAR, with fantastic technique and a perfectly controlled, agile and polished voice. However, it's only too bad that her music has always been mostly rubbish: her two first and two more recent albums are very much a matter of over-promotion and quantity over quality, and her best moments (Sasha Fierce and 4) seem to have been accidents, rather than signs of improvement.

As for the rest of the bunch... Mandy Moore is a great actress with a tiny little voice, Avril Lavigne is still a talentless little troll with an insufferable personality and Ashlee Simpson is back where she belongs: absolute obscurity.