Kendrick Lamar has “new material” dropping soon, say Danish festival Roskilde.Lamar was announced yesterday (December 30) as a headliner for the festival’s 50th anniversary event next summer.In the festival’s announcement post for the line-up reveal, under a section entitled ‘new material on the way’, they wrote: “Lamar first visited Roskilde Festival in 2013 when he played an unforgettable concert on the Arena stage.