Metallica is offering a free download of a 1986 concert from the tour that supported the release of their watershed album, Master of Puppets. Recorded Sept. 21, 1986 at London’s Hammersmith Odeon, the concert featured John Marshall (Kirk Hammett’s then-guitar tech) on rhythm guitar, as James Hetfield had recently broken his arm in a skateboarding accident. The date is also notable in that bassist Cliff Burton died tragically in a bus accident less than one week after the concert was staged. Notable tracks include “Welcome Home (Sanitarium),” “Seek & Destroy,” “Whiplash,” “Creeping Death” and the title track. The band has also posted several video clips from sessions circa 2008, during the run-up to the release of the Death Magnetic album. Click here to download the concert mp3s. You can sample the 2008 videos below.