Songfacts®:

• Originally written and recorded by the rock singer-songwriter and pianist Leon Russell for his 1970 eponymous first solo album, this song is a plea for forgiveness and understanding from an estranged lover. It soon sprung a series of cover versions including ones by Andy Williams, which peaked at #82 on the Billboard Hot 100 in 1971, Donny Hathaway, whose interpretation is considered one of his signature songs, and the Carpenters who made it the title track of their 1972 album. Later in 1993 Ray Charles recorded a poignant version of the song for his My World album. His rendition warned him a Grammy Award for Best Male R&B Vocal Performance. Whitney Houston performed the song for the troops and their families returning from the Gulf War on March 31, 1991 and later recorded an upbeat disco version for her 2009 comeback album, I Look to You.
• Donny Hathaway was Winehouse's all-time favorite artist and during the spring of 2009 she recorded her own interpretation of Hathaway's version in one take, at a studio that she had built at home in her attic. Winehouse laid down the track in the midst of her struggles with drugs and alcohol and the recording ended up as the closing track of her first posthumous album, Lioness: Hidden Treasures. "She said to me, we can make the new album here," the song's producer Salaam Remi recalled during a listening session. "We don't have to worry about the paparazzi. She was just lying down on a couch, with the mic in her hand and by about halfway through the song she was crying, really weeping, with makeup running down her face." Remi took this bare recording of just Winehouse and guitar and added further production to it.
• Winehouse previously referenced her regard for Donny Hathaway when she sings on "Rehab":
  
  There's nothing you can teach me
  That I can't learn from Mr. Hathaway
• After this song finishes playing, we hear a snippet of Winehouse talking to Remi, discussing her hero. "Donny Hathaway," we hear her say. "It was like he couldn't contain himself... he had something in him, you know."