David Foster, the hit-maker who has won 16 Grammys, three of which with Whitney Houston, revealed the intricate details of how their collaboration on the ballad, "I Will Always Love You," became the epic anthem of Houston's career.
In an interview with "Nightline" anchor Cynthia McFadden, the Canadian music producer-songwriter said Houston blew him away when they recorded the song, "I Will Always Love You," in 1992. Her mother Cissy Houston was listening on the sidelines.
"It was like 'BOOM,'" Foster said. "I was standing right beside Cissy, and she turned to me, and she said, 'I don't know who you are and why you are here or what you are to me, but you are witnessing greatness right here.' And she was right."
"I don't think she just meant that her daughter was great. She meant that this was the pinnacle of what she believed what would be her daughter's success and she was right."
"I Will Always Love You," written and performed by Dolly Parton in the '70s, ended up as a late addition to the score while Foster and Houston were working together on the soundtrack for the 1992 blockbuster, "The Bodyguard" -- Houston's first film.
Foster said actor Kevin Costner, who produced and co-starred in the film, suggested they use "I Will Always Love You" as the signature ballad after the '60s soul hit, "What Becomes of the Broken-Hearted," fell flat with Houston. Foster said at the time he had never heard of "I Will Always Love You," but once he listened to Linda Ronstadt's cover, he said he was "immediately" struck with inspiration.
I made a demo ... ran to [Houston's] trailer, because I was so excited. I said, 'Whitney, I've got it, I've got it, I've got it,' and I played it for her. And, of course her face lit up because she knew and I knew that I had got it," Foster said.
When they first started going over the song, Foster said Costner suggested she sing it a capella for the movie, which the music producer scoffed at at the time.
"I thought using no music at the beginning was a stupid idea," Foster said. "And I hate being wrong, but when you're wrong you got to be wrong big because when you're wrong big, it means you get to be right big too and the song certainly ended up being very right."
Foster and Houston's version of "I Will Always Love You" earned the duo three Grammys and was later listed as one of Billboard's "Greatest Songs of All Time." Mere hours after Houston's death on Sunday, the song topped iTunes charts.
Foster said he first met Houston at a party thrown for her by famed record producer Clive Davis. She was "glowing," he said, and just 18 at the time. Davis had discovered Houston singing in her mother's nightclub, signed her to Arista Records in 1983 and remained her mentor.
"She probably trusted [Davis] more than anyone else in the world, barring her parents," Foster said. "He was there every step of the way even through the good times and the bad times and he never, never, ever, ever, ever gave up on her."
While Houston reportedly had a rocky relationship with her other partner in life, ex-husband and R&B singer Bobby Brown, Foster painted a different picture of the couple, at least, as he saw them in the recording studio.
"Bobby and Whitney were a team," Foster said. "He was incredibly supportive of her at all times."
In more than three decades of producing, Foster has collaborated with other iconic female artists, including Barbara Streisand, Celine Dion, Diana Ross and Natalie Cole, but Houston, he said, was a music "genius" in her own right. Their last collaboration together was on Houston's 2009 single, "I Didn't Know My Own Strength" -- her last hit released before her death.
"Celine would give me exactly what I asked for, which just thrilled me, as an egotistical record producer. Thank you, Celine," Foster said. "When I would ask Whitney to do that, she would give me something different than I asked for. And 99 percent of the time, it would be something better than what I asked for... that was the genius, part of the genius, of Whitney Houston."