Metallica "trolled" their fans in the most loving of fashions at the Orion Music + More Festival in Detroit earlier this month. They played a secret show at their own fest, billing themselves as Dehaan, a band no one but Metallica had heard of that hailed from Baltimore. It was a brilliant "trick" and one that fans certainly loved. Now Metallica are taking you behind the scenes of the rehearsal for Dehaan's debut in a newly posted video (seen below).

Dehaan, aka Metallica, played the 'Kill 'Em All' album from back-to-front for the set and surprised many at Orion, so much so that a rush toward the stage ensued as word about the surprise performance spread through the festival grounds.

Ever the generous metal band, Metallica have shared the footage of their "Dehaan" rehearsals. Check out the rehearsal studio footage of James Hetfield and the boys playing 'Hit the Lights' and 'Phantom Lord.' The video is about 13 minutes long, but it certainly pulls back the curtain and lets the fans in on the Metallica practice process.

Yes, even a band like Metallica, with four decades of history and experience, needs to rehearse, especially since they don't play some of these classic songs every set or every year. Hear that, aspiring metal bands? Practice makes perfect. Metallica are living proof of that fact.