Metallica will release a new song today (20.06.14) ahead of their headline set at Glastonbury festival.

The 'Enter Sandman' band, who will be the first heavy metal act to top the bill at Worthy Farm next week, have released 'Lords of Summer - First Pass Version' via Blackened Recordings, which the group first debuted in March at a concert at Parque Simon Bolivar in Bogotá, Colombia.

The new recording clocks in at eight minutes and 20 seconds and recalls the group's thrashier '80s offerings, with a fiery solo from lead guitarist Kirk Hammett.

The band's drummer Lars Ulrich told Rolling Stone that the song is ''fairly representative of where our creative head space is at right now.''

It is not yet known if the track, which is their first new material in six years, will be included on Metallica's next album, the follow-up to 2008's 'Death Magnetic' album.

Footage shot by a member of the audience in Colombia saw the song posted online and it was shared between fans before Metallica put out a ''garage demo version''.

A post on the band's official Facebook page in March revealed the group's plan to unveil a new track.

A picture of all four members of the band - frontman James Hetfield, plus Rob Trujillo, Lars and Kirk - was accompanied by the caption: ''Working out the kinks in the new song that we'll be debuting in South America in a couple days.''

Earlier this year, Metallica guitarist Kirk said that the band ''have to'' start working on their next album.

When asked if the record would likely be released next year, Kirk replied: ''I'm f***ing up for it, man.''