Hayley Williams has a remarkable voice which is best seeen below in the acoustic version of the song. She hits some amazing notes and has an infectious "stage presence." At only 18 (and from Meridian, MS.) she has become one of the more recognizable voices in altenative music.
Paramore is not some fringe band. They were nominated for a grammy and they have two songs in the "top 100 songs" downloaded on itunes.
Below is the music video for "Misery Business which has been watched over 22 million times on itunes. Below is an acoustic version of the same song which really shows of Williams' chops.