Folk festivals may have started out as hippie havens, but they've expanded in recent years to cover a broad range of sounds and styles – from indie rock and alt-country to hip-hop, soul and world -- that still stay true to the roots of folk as the music of the people.

The Calgary Folk Festival is celebrating its 31th anniversary from July 22-25 at Prince's Island Park and has assembled a nicely diverse line-up that includes 68 different groups from 14 countries on seven stages performing for over 50,000 fans.

The indie kids will be lining up to be wooed by Stars' neo-new wave, watch St Vincent's Annie Clark rock out and see the Avett Brothers get their bluegrass on. Hip-hop hippies will be dancing to Michael Franti and Spearhead; globaltronica dancers will be getting down to Natacha Atlas and turntablist DJ Logic; folk fans will throng the stage for Oscar-winning boy-girl duo the Swell Season; Calgary's alt-country crowd will turn out for Alberta hero Corb Lund and everyone will come together to be killed softly by the songs of soul legend Roberta Flack.

For a full festival lineup and ticket info, visit the Calgary Folk Music Festival website.