While introducing it in concert, Gordon Lightfoot called it his "first real good song." Peter, Paul & Mary lent their vocal harmonies and guitar playing to an excellent version of it. Sara Watkins and Eva Cassidy sing it impressively, as well. The tune: "Early Morning Rain." Those versions are among the better known ones.
Dr. Corn's Bluegrass Remedy recorded a somewhat obscure concert version of it that's worth seeking out. Their version of it on the "Live (It'll Tickle Your Innards)" album showcases the ensemble's vocal and bluegrass pickin' abilities. Listening to them perform it in concert reminded me of how strong Lightfoot's tune about watching planes while not being in the best of spirits is. Regardless of who sings it, though, the tune's wistfulness should resonate with the listener.
