Guster guitarist Adam Gardner joined Wille Nelson & Family, Alison Krauss and Union Station and Jerrry Douglas on stage for a show-closing medley last night in Bangor, ME. The musicians, who have been on tour together for the past few months, were performing in the city as part of its Waterfront Concert Series, while Gardner was at the show with Guster’s greening and grassroots outreach organization Reverb. The medley featured a number of traditional sing-alongs like “I’ll Fly Away” and “May The Circle Be Unbroken.”

Nelson and Krauss will continue their tour tonight with a show at Meadowbrook in Gilford, NH. Reverb will be on tour all summer with a number of acts, including Phish, Dave Matthews Band, Jack Johnson and Linkin Park.