According to this blog post, women in popular music are sexistly scored according to something like the rule/policy that we can graphically represent by the territory under the following frontier:
other problems with the blog-posting, i.e., setting aside whether the rule allegation is correct, but in fact, I believe its frontier/rule allegation isn't correct, as any even half-way serious (albeit speculative) scatter-plotting would have shown. All your Kate Bush's and Siouxsie's and Aimee Mann's are in the top right quadrant of the graph. Probably Madonna, Gwen Stefani, Roisin Murphy, Chrissie Hynde, Feist, Jenny Lewis, Natasha Khan, and many others are there too. And super-talents with somewhat quirky looks from Tracey Thorn to Bjork to PJ Harvey to (Dresden Dolls') Amanda Palmer, to Carey and Tracyanne Camera Obscura to Tegan and Sara to Angel Deradoorian (all of whom I personally find very attractive - these are geek-goddesses at the very least) are hardly unheard of. Even if enough SOBs score them low on looks though, they've got talent points to burn and should still be, by consensus, above the frontier in the top left quadrant of the graph.
Of course, saying all this has involved us looking beyond our target blogger's principal focus: the true bubble-gum pop market. I agree that that arena is perhaps the most brutally superficial, 'looks first' market of all. Looking like Justin Timberlake or Gwen Stefani or Posh Spice or Rihanna (plus lots of luck) can get you initial success in that marketplace. But sustaining that success normally means proving that you've got real talent after all. Showing that you're more than just a pretty face or a slinky mover is, in most cases, almost like starting all over again. Not 1 in 20 tween-/teen-courting pop-stars gets over that hump, and then goes on to have a substantial, expanding career. That appears to be appropriate, and controlling for (oscillating through the decades) skew by sex in the bubble-gum pop market, I'd need to see serious evidence that that very difficult next step works in any especially sexist way. My own sense is that Justin Timberlake, David Cassidy, every New Kid on the Block, and so on, faced at least as much skepticism and vague resentment as Beyonce, Britney, the post-Spice Girls, and so on did. Getting off the brainless/talentless bimbo track - 'No, really, my looks got me in the door, but I can really play/sing etc., I'm Elton John, I'm Streisand, I'm Agnetha....' - after you've won the bimbo lottery isn't easy for anyone.
In my view, then, rather than allege spurious rules, it would be better just to look at plausible scatter-plots of both male and female popular musicians (i.e., on the same looks/talent axes). Plots we could agree on (supposing consensus about looks and talents scores could be found) might in fact be rather different for male and female stars. I'd guess, for example, that we'd find/agree that there are few, if any truly homely female stars. A sexist factor in culture at large - a double standard about looks that actors/television presenters/news-readers etc. have long complained about - could and probably does apply in pop music too. But what do the talent score distributions for the sexes in music look like after we control for looks scores? Roughly the same? Do they at least have similar means? Is either distribution skewed, and if so how exactly? What are the variances? Studying this would appear to be an interesting project, unlike some others.