“A Song for You”—a slow, pained plea for forgiveness from an estranged lover, as Wikipedia puts it—is a 1970 pop classic song written and originally performed by Leon Russell, one of the most gifted pop songwriters and session musicians of the 1960's and 1970's.
In the video, from the above mentioned DVD, Willie and Leon take a verse of the song and let Ray finish it up, as only The Genius could (he also performed the song in his 1993 album “My World”). During Charles’ performance, as shown in the video, Willie was moved to tears, and I can easily understand why. How about you?