"I always loved world music - I used to get stoned and listen to the Mystere de Voix Bulgare Choir in the 1960s, all my friends did, " Boyd said.

BBC: Making the sound of the '60s

The 2013 festival included a tribute to Dundee singer-songwriter Michael Marra and performances by The Mavericks, Mary Chapin Carpenter, Old Crow Medicine Show, Salif Keita, Kate Rusby, Carlos Nunez, Dougie MacLean, Roddy Hart and the Lonesome Fire, Le Mystere des Voix Bulgares and Aimee Mann.

BBC: Mary Chapin Carpenter