Since parting ways with guitarist Charlie Hitchcock, the members of Particle have kept a relatively low profile, figuring out the next stage in the groups evolution. Last night, however, keyboardist Steve Molitz emerged for a performance with another group currently on a soul searching mission, Blues Traveler. Molitz joined Blues Traveler on But Anyway at the end of its set at West Hollywood , CAs House of Blues. John Popper has collaborated with the Particle People on several occasions, including a pair on northeast performances last Halloween. Tonight, Blues Traveler will perform at San Franciscos Fillmore Auditorium.