Watch the film preview on NME.COM now
Gig will now take place in London rather than Vienna
Mary J Blige, Chris Brown and Natalie Cole not expected to perform
Late singer to 'reappear onstage' as secret part of show - video
Natalie Cole and Sister Sledge also signed up for concert
Singer is laid to rest at 200-strong private ceremony
Certificate now features 'injection by another' as cause of death
Officials rule that the self-styled king of pop was intoxicated by Propofol anaesthetic
World record attempt happening in London on what would have been singer's 51st birthday
Released court papers reveal singer's death was a 'homicide'