Unlock the following characters for purchase by performing the corresponding tasks:
CHARACTER - HOW TO UNLOCK Billy Corgan - Play the song 'today' in the band career. Hayley Williams - Play the song 'misery business' in the vocals career. Ozzy Osbourne - Play the ozzfest gig in the vocals career. Rockubot - Complete the drum career. Skeleton - Complete the vocals career. Sting - Play the song 'demolition man' in the bass career. Ted Nugent - Beat his guitar battle in the guitar career. Travis Barker - Play the song 'dammit' in the drum career. Zakk Wylde - Beat his guitar battle in the guitar career.