The festival's on this weekend from Thursday to Sunday - there should be a few things that would be worth a visit. The official calendar's supposed to be at http://www.merchantcityfestival.com (not working right now) and we've distilled down what we reckon is worth taking cameras to at our calendar.
Everything seems to be advertised as a free event, but some of the stuff is indoors at specific venues as opposed to street entertainment and one in particular piqued my attention when it was advertised as being in support of a community gallery project or something similar, so I'm taking that with a pinch of salt.