Have a great time. I saw them in my home town (Manchester, UK) last year, but on this tour. One of the best gigs I've ever been too (and I've been to a few). Are they doing it "in the round" here? Was quite simply amazing.
Gong are a Franco-British progressive/psychedelic rock band formed by Australian musician Daevid Allen and they played in Brazil in 2007. Metallica is an American heavy metal band from Los Angeles, California, formed in 1981 and rumoured to be playing in Bs As this weekend. No contest IMO. HTH HAND