Yonder Mountain String Band has spent this past week on the road with fellow newgrass band Infamous Stringdusters serving as their opening act. Each night of the tour has featured some band crosspollination. On Wednesday night, the two groups performed at Portland, ME’s State Theater. Longtime Yonder collaborator Darol Anger played fiddle throughout Yonder’s two-set show while Infamous Stringdusters’ Andy Hall (dobro) and Jeremy Garrett (fiddle) emerged at the start of Yonder’s second set for “No Expectations,” “Funtime” and “Steam Powered Aereoplane.”

The following night the two groups appeared at South Burlington, VT’s Higher Ground. At the end of Yonder’s show, all the members of The Infamous Stringdusters sat in with the evening’s headliner for an encore that consisted of “High Country Funk” as well as a medley of “Ruby” and “Follow Me Down To The Riverside.” Then it was off to Clifton Park, NY’s Northern Lights where members of the Stringdusters joined Yonder for two segments. First, Andy Falco (guitar) and Chris Pandolfi (banjo) emerged for “Years With Rose” and “Cuckoo’s Nest” during Yonder’s first set, and a bit later in the set, Jeremy Garrett (fiddle) and Andy Hall (dobro) appeared on “New Horizons” and “Come Together.”

Finally, last night the two groups hosted a Halloween-themed show at New York’s Best Buy Theater. Partway through their performance, Yonder bassist Ben Kaufmann reminisced about his time living in New York, including when he walked from his apartment to see Phish at Madison Square Garden. At the end of Yonder’s second set, all the members of The Infamous Stringdusters as well as Punch Brothers banjo player Noam Pikelny emerged for a set-closing “Pretty Daughter” and “Death Trip.” All the musicians then returned for the encore of “Up On The Hill Where They Do The Boogie” and “Let Me Fall.” Pikelny—a longtime friend of the Yonder family and former member of Leftover Salmon—will tour with The Infamous Stringduster’s Chris Pandolfi later this year.

The Infamous Stringdusters will celebrate Halloween at Allston, MA’s Brighton Music Hall tomorrow. The group will the join Yonder for a performance at Pittsburgh, PA’s Stage AE on Wednesday.