While the members of Umphreys McGee and Sound Tribe Sector 9 still seem hesitant to collaborate during their regular co-headlining gigs, the groups The Second Set after parties are an altogether different story. A night after Umphreys McGee guitarist Jake Cinninger joined STS9 at New Yorks Blender Theatre, members of STS9 returned the favor during Umphreys McGees late night gig at Philadelphias The Fillmore at the TLA this past Friday. Partway through Umphreys set, STS9 bassist Dave Murphy and drummer Zach Velmer stepped in for Ryan Stasik and Kris Myers, respectively, for a take on Push the Pig. STS9 and Umphreys McGees co-headlining tour will continue this Wednesday at Myrtle Beach, SCs House of Blues. For more on the groups tour, please visit Umphreys McGees official blog.