Def Leppard have always thought big. And their best tunes have always sounded as if they were written with the arena in mind. It was their meticulous collaboration with producer Robert John “Mutt” Lange that brought them to previously unimagined commercial and artistic peaks with Pyromania and Hysteria. On their own in 2008, 20 years since the glory days and producing themselves, the band remains disciplined if not quite as wide-screened in their audio attack. A street-walking stomper like “C’mon C’mon” packs a dense punch even with its layers of backing vocals and walls of guitars. The duet with country star Tim McGraw on “Nine Lives” is novel in theory: a country star meets the heavy metal kids? Its execution is satisfactory if not revelatory; it doesn’t need McGraw to get the song across. “Go” catapults with the energy of old, while “Love” is the power ballad any loyal fan knew they had in them. Singer Joe Eliot’s in fine voice and the band are hardly showing their age, just their era. For fans, it’s like running into an old friend and even though they haven’t seen each other in years feels as if the time in between never happened.