From Wikipedia:
Jem was an American animated television series that ran from 1985 to 1988 in U.S. first-run syndication. The show is about a singer named Jem, her band the Holograms and their adventures. Catch phrases from the show included "Showtime, Synergy!" and "Truly outrageous!" (the latter usually associated with supporting character Kimber).

Despite the fact that the show was originally designed by Hasbro for the purpose of marketing a line of dolls, it employed several interweaving storylines and a complex backstory — both unusual in an animated television series during the 1980s. The show also features one-minute music videos, tying it in with the concept of MTV and its burgeoning popularity.

Jem/JerricaJem/Jerrica

KimberKimber

AjaAja

ShanaShana

RioRio

And the Holograms' rivals, The Misfits:

The MisfitsThe Misfits

PizzazzPizzazz

RoxyRoxy

StormerStormer