Keller Williams co-headlining tour with Yonder Mountain String Band will conclude this weekend with a high-profile gig at Morrison, COs Red Rocks Amphitheatre. As expected, Williams has regularly collaborated with the members of Yonder throughout the summer, especially on a series of quirky covers. Last night, Williams and Yonder performed at Flagstaff, AZs Pine Mountain Amphitheater. Williams played first and, at the end of the evening, joined Yonder on a cover of Kiss I Wanna Rock And Roll All Night. This evening Yonder and Williams will closeout July with a free performance as part of Salt Lake City, UTs Twilight Concert Series.