WXPN in Philadelphia will broadcast live from two music showcases during day two of nonCOMMvention, the annual conference for pubradio’s Triple A music stations. XPN Free at Noon, a weekly live concert series that is open to the general public, is a double-header of Guy Sebastian featuring Steve Cropper, followed by the Derek Trucks Band. Four acts are on the bill of tonight’s showcase: Rhett Miller, The Avett Brothers, Pete Yorn and Delta Spirit. Tune your browser to the live webcasts here.