Particle got some help from a number of special guests during their post-Phish late night show on the Spirit of Chicago yacht on Saturday night. The band was joined by Umphrey’s McGee drummer Kris Myers, Brothers Past guitarist Tom Hamilton, guitarist Fareed Haque, drummer Greg Fundis and saxophonist Marty Gierczyk for a cover of the Grateful Dead’s “Scarlet Begonias,” a “Windy City” jam and Grant Green’s “Jan Jan.”