Grohl and his band Foo Fighters appeared at the party's annual gathering in Charlotte, North Carolina before Obama accepted the party's nomination to run for a second term as president.
Grohl and his band played a special two-song acoustic set beginning with their 1998 single 'My Hero', which Grohl introduced by saying: "It's an honour to be here. I think this song makes perfect sense here tonight."
The band then completed the set with their 2011 song 'Walk". The previous night they had performed a three-hour, 35-song set at the Rock the Vote show, also in Charlotte.
Mary J Blige, James Taylor and Marc Anthony were the other artists to perform at the convention.

© Rex Features / KeystoneUSA-ZUMA/Rex Features

© Alex de Mora
Foo Fighters headlined Reading Festival last month, where they claimed that the gig was "the last show for a long time".
However, since that performance they have added a number of US festival dates in September.



