The "Disney Era" of Teen Stardom
The realization Disney came to is that youth love their favorite stars in a different way than adults do. When an adult loves a star, say Reese Witherspoon, they love the body of the work of that star, maybe find her attractive, but don't tend to get too emotionally attached. Kids on the other hand LOVE not just the work of the star, but the actual star him/her self. They are gonna follow whatever that star does, no matter how awful it is. That realization is what causes Disney to exploit and overexpose all of their current stars, and in some cases to just poach stars from other networks (e.g. Corbin Bleu). Don't forget that Nick blatantly ripped them off by founding their own Nickelodeon record label and putting out show soundtracks sung by the stars on it. E.g. The Drake and Josh soundtrack sung by Drake Bell and Emma's Unfabulous soundtrack. But it seems to me that of all the singing/acting teen stars, none of them are really good at both. Here's a noncomprehensive list:
Hilary Duff - A good actress, and I've defended her voice before, but it's not a great voice. It's just a voice that has had a lot of great songs written for it. Would she be more successful in the mainstream now if not for overexposure/teen pop? I dunno.
Lindsay Lohan - A really great, underrated actress. I think her two albums were OK, but they certainly didn't meet to any kind of great success. I do think she has a lot of personality and charm as a singer and as an actress, which makes her a rare, welcome exception. Yet the fact remains that her singing career was essentially a flop.
Brie Larson - What personality and liveliness as a singer. A great writer! Seemingly impossible not to love! Yet wooden, and not good, as an actress.
Miley Cyrus - I believe my opinions on her acting AND singing are well known by now.
Aly & AJ - Alyson Michalka is a great actress, but a robotic singer. AJ Michalka is a terrible actress but a great singer. So together they are great at both!
JoJo, Emma Roberts, Sara Paxton - The three main stars of Aquamarine. JoJo is a good singer, but if her work in Aquamarine is any forecast for the future, might not have a long career as an actress. Emma R my opinions are known on. Sara Paxton (star of Darcy's Wild Life) is pretty good as a singer and an actress, but not great as either (at least in my opinion).
Ashlee Simpson - Good as a singer, great songs and lyrics. Why, oh why, did she feel the need for that stint on Seventh Heaven? Suffice to say, not a good actress, at least not judging by that yardstick.
Ashley Tisdale/Vanessa Ann Hudgens/Zac Efron/Lucas Grabeel: The stars of High School Musical. All the singers were good enough for what the movie required (wait, except Efron I guess), but none are great singers. Not likely to have long music careers, unless they turn out to be killer songwriters, or hire the best ones anyways. All four, except Vanessa, are good actors.
Almost all of the other Disney stars have at least SOME songs (Christy Carlson Romano, back in the day, Anneliese Van Der Pol, Raven, etc.)
Disney actresses who don't sing:
Kay Panabaker (obligatory Kay P reference)
Jamie Lynn Spears is on Nick, close enough (though a forthcoming singing career seems really likely)
American teen pop stars who don't act:
(Jesse McCartney was on Summerland)
Seriously, the incidence is so high it's scary. So I guess the reason such a low percentage of them are good at both, and none appear to be legitimately great, is that the kids are being forced to go into both even when they are only any good at one. This fleshes out and hopefully explains better some stuff I've been talking about on the Rolling Teenpop thread lately. Let me know if I'm missing anybody/anything obvious up above.