James Hetfield (left) and Kirk Hammett at a Metallica concert. Pic/AFP

When bands are changing gears and absorbing electronic sounds to keep up with time, Metallica — one of the heavy metal greats — boarded a time machine to revert to their teenage years through their latest production, Hardwired...To Self-Destruct (Blackened Recordings). The sound flies to the early ’80s when Dave Mustaine (Megadeth) co-wrote a few tracks for the band. The content of the album is borrowed in bulk from Ride The Lightning and Kill ’Em All — the debut album of the band.