Gwen Stefani rose to fame as the frontwoman of No Doubt, before launching a successful solo career, but perhaps she's got a certain girl group on her mind.MORE: Gwen Stefani's son appears in very rare photo with sister - and he looks so differentIn a small video uploaded to her Instagram feed, the Slow Clap singer modelled a look very different than what she usually wears on a checkerboard background.The star emulated a ska style, as she wore a yellow flannel shirt over her shoulder and a yellow