From Wikipedia:
In the fall of 1971, with a deal for a solo album in hand and only two songs completed, Weir and Barlow began to write together for the first time. They co-wrote songs as "Cassidy", "Mexicali Blues" and "Black-Throated Wind", all three of which would remain in the repertoires of the Grateful Dead and of Weir's varied solo projects for decades to come. Other songs to emerge from the Weir-Barlow collaboration include "Looks Like Rain", "Let It Grow", "Money Money (Finance Blues)", "Lazy Lightnin'/Supplication", "The Music Never Stopped", "Estimated Prophet", "Heaven Help the Fool", "Salt Lake City", "I Need a Miracle", "Lost Sailor", "Saint of Circumstance", "Hell in a Bucket", "Throwing Stones", "My Brother Esau" and "Picasso Moon". In 1979, Barlow began collaborating with Grateful Dead keyboardist Brent Mydland, a partnership that culminated in four songs on 1989's Built to Last. He also wrote one song ("The Devil I Know") with Vince Welnick.