Heavy rock legends Metallica have released their first new material in three years to celebrate their summer (14) festival shows.

The Enter Sandman hitmakers are scheduled to headline Britain's Glastonbury Festival on Saturday night (28Jun14), marking the first time a heavy metal band has topped the bill at the iconic event.

The band has now released a song called Lords of Summer, their first new material since 2011's Lou Reed collaboration Lulu, to celebrate the achievement.

Drummer Lars Ulrich tells Metal Hammer magazine, "It's fun... It's a good song... It's kind of written for this tour. It's... kind of about being outdoors and festivals and all this stuff. And here we are getting into the summer and it's not raining too much and, apart from Finland, it's nice and warm."

As well as Glastonbury, Metallica is also slated to perform at Britain's Sonisphere next month (Jul14), as well as legs of the event in Switzerland, Italy and Poland, and several other European festival dates.