A negative part of representation in the pop music industry is that women are treated as sex symbols, especially in the music videos.
Katy Perry is an example of using Laura Mulvey's theory of the "male gaze" where the viewer looks at the women through the male's point of view, women would usually be seen as an object.
This can continue as the women ages, until they are "too old" to be seen as a sex symbol anymore, as seen in the case with Madonna, however she tries to overcome it by reinventing her look over the thirty years since she has been famous, this could be a positive because it shows she is strong and is keeping people interested in her.
It's not just individual people in the pop music industry but it can also be bands as well, in the case with the Black Eyed Peas, where the woman in the band (Fergie) is using her gender to maybe encourage the "male gaze", combining it with another theory which is the "female tease" theory where the women uses her gender to her advantage as some sort of power over the male, but it is argued that women who do this further create a patriarchal society where men are more dominant than the women.
Another band where the men are more dominate than the women is No Doubt where the lead singer who is Gwen Stefani is seen to be wrapped up around by the men, this could be to show that she is being protected by the other men and maybe seen as the weaker sex.