I found this on Google. It might give you a place to begin?

Tucson Folk Festival

The Tucson Kitchen Musicians Association (TKMA) invites all music lovers to enjoy 20 hours of free, live acoustic music on five stages in downtown Tucson at the annual Tucson Folk Festival, one of the largest free festivals in United States. Started in 1986, the Tucson Folk Festival features hundreds of local, regional, and national musicians performing live music, uplugged and plugged in, for more than 10,000 fans. Portions of the festival are broadcast live on Tucson's community radio station KXCI 91.3 FM.
Date: May 4 -5, 2013
Contact: Jim Lipson, TKMA President, at jimlipson@yahoo.com or (520) 271-6943
Number of volunteers: 250
Estimated attendance: 10,000

It was on this page: http://www.visittucson.org/media/research/eventprofiles/

I also found a site for The Tucson Kitchen Musicians Association: http://www.tkma.org/tkma/index.html

Good luck!
rags