The audience has had a couple of weeks to devour the numerous new acts on the Roskilde poster. Today we announce two solid bands who add more rock, riffs and energy to an already bulging music programme.

BIFFY CLYRO (UK) plays epic guitar rock full of addictive melody lines, soaring ballads and a stadium-rocking feel. The three lads turned on the amplifiers for the first time in 1995, but it is particularly with the latest albums – not least Only Revolutions from 2009 – that they have broken through the stratosphere and now feel at home in the highest rock altitudes.

MESHUGGAH (S) plays one of their few summer gigs at Roskilde Festival. The Swedish metal band is widely praised for its technical, mathematically sharp metal. The latest release Alive shows how extreme and uncompromising Meshuggah is live – so we are delighted to have one of Scandinavia's most prestigious metal extremists back.