S PRCSS are one of the coolest bands that I know little about. Their mysterious nature — do a web search and see how much you dig up — makes it quite rad to see them play. I knew nothing about this band until I saw them, sometime last year, at the Lighthouse (itself a fairly off-the-beaten-path venue). Since then I have managed to piece together bits of information about the group. Seems they were a Philly-based band some time ago, but either broke up or became basically inactive, but have gotte…