Successfully complete the indicated task to unlock the corresponding song:

18 And Life by Skid Row: Successfully complete the first set and do the encore.
Because It's Midnight by Limozeen: Successfully complete Amp Warmers and do the encore.
I Wanna Rock by Twisted Sister: Successfully complete String Snappers and do the encore.
Round And Round by Ratt: Successfully complete Return Of The Shred.
Wrathchild by Iron Maiden: Successfully complete Relentless Riffs.
Play With Me by Extreme: Successfully complete Furious Fretwork.