A good question, that caused me to go out and find these articles:
http://adequateman.deadspin.com/how-...val-1697067459
http://diymusician.cdbaby.com/musici...usic-festival/
http://blog.jammob.com/want-to-start...sic-festivals/
http://drownedinsound.com/in_depth/4...st-kept-secret
http://drownedinsound.com/in_depth/4...l-2--green-man
http://drownedinsound.com/in_depth/4...-beacons-metro
http://drownedinsound.com/in_depth/4...--pop-montreal
http://drownedinsound.com/in_depth/4...estival-5--s-n