The show -- dubbed "Freeze 'Em All" by the band -- took place inside a dome to protect the crowd from snowfall and harsh winds. Despite the conditions, the show was completed without any problems.
To respect the icy continent's fragile environment, the concert was held without traditional amplification, in accord with international Antarctic protocol. Amplifiers were enclosed in isolation cabinets, with the sound transmitted to the audience via headphones, much like the "silent discos" sometimes found at music festivals.
By playing the non-traditional gig, Metallica becomes the first act to play on all of the Earth's seven continents.
On a much smaller scale, the United States' McMurdo Station has been hosting open mic nights in Antarctica for some time, and in 2007, a five-piece band of British scientists called Nunatak claimed to have played the continent's first rock concert.
In 2006, Fall Out Boy planned to play an Antarctic gig, but had to cancel due to (unsurprisingly) uncooperative weather.
Here's the set list from Metallica's Dec. 8 show in Antarctica:
For Whom the Bell Tolls
Sad but True
Welcome Home (Sanitarium)
Master of Puppets
Nothing Else Matters
Seek & Destroy