The 2004 track helped catapult the Grammy winner to fame and it became the first song to stay on America's Billboard Hot R&B/Hip-Hop Songs music chart for over a year, but Alicia's hit almost belonged to someone else.
"There's a really funny, amazing story around this song," Alicia revealed during an interview with Stereogum. "I think we were on the same label at the time. She (Christina) reached out and was like, 'Would you write something for me?' And then it came through so many emails."
"What a voice! I know I could write something fire for her. So time passed and I hadn't written the song yet. And (the label) was like, 'Do you have anything for Christina?' I remember I had just recently written 'If I Ain't Got You'."
Alicia eventually went on to pen Impossible for Christina's 2002 album "Stripped", but that song was born out of the conflict over "If I Ain't Got You".
"I told my A&R (manager) at the time, 'Let's play her If I Ain't Got You'. He said, 'Are you f**king crazy? We're not giving her that song. Are you out your mind?'," she recalled with a laugh. "I was like, 'Why not? I'll write a hundred more of those, it's fine. I think she should hear it. I don't really think it's a big deal'. But I thought, 'Fine, I'll go write another song'. So I went off and wrote 'Impossible'."
Alicia cherishes the moments she shared at the recording studio with Christina while they laid down the vocals for "Impossible", adding, "I went to cut it with her and I love how she sounded on it. It was such a cool vibe for us to be able to work together during those times... Iit's really important to be in the same space to just get all the energy. That was great. She sounded so good and she's very special too."
"But I will never forget that I would have given away 'If I Ain't Got You'. Isn't that crazy?"