Her death came hours before she was due to appear at an annual pre-Grammy party that introduced her to the industry decades ago and was expected to honour the six-time Grammy winner.
The 48-year-old singer had been making the rounds in the days before the event, appearing at rehearsals and offering advice to singers Monica and Brandy.
On Thursday, she appeared with fellow singer Kelly Price on stage at a Hollywood club, where she sang the hymn ‘Yes, Jesus Loves Me’ to loud cheers.
With Houston’s daughter Bobbi in the audience, the women shared a hug and talked about their lives and families on the night, Price recalled on Saturday.
Houston spent hours standing on the side of the stage at the event honouring R&B music then joined partygoers on the dance floor, she said.
“Whitney on Thursday night was one of the girls. She was happy,” Price said.
“She was the Whitney I always knew.”
Soul singer Kenny Lattimore, who co-hosted the& event, said Houston seemed to be having a good time, making her sudden death “such a shock”. He said she did not appear to be having any issues.
Houston struggled for years with addiction to cocaine, marijuana and pills and the years of hard-living took a toll on her voice.
During rehearsals for a pre-Grammy event on Thursday, Houston appeared dishevelled, she sweated profusely and her breath smelled of alcohol and cigarettes, said a source.
Despite more than a decade of problems, including her divorce from Bobby Brown and numerous instances of erratic behaviour, Houston was working toward a potential comeback. She had just completed work on a remake of the film Sparkle, a project she’d worked to develop for years.
Yet some speculated she was under the influence after the Thursday club appearance, when paparazzi snapped Houston leaving and looking the worse for wear. Price called the rumours “totally untrue”.
There was a family feel to the gathering, she said: “Our kids were there.” Price said she and Houston were planning another reunion, and that she was to appear at the pre-Grammy gala thrown by her longtime mentor, Clive Davis, on Saturday night.
Davis had expected that Houston would sing at the party, which went ahead as planned, he explained, because the diva would have wanted it that way. It took place in another part of the hotel from where her body was being examined by coroner’s officials.
“I am personally devastated by the loss of someone who has meant so much to me,” Davis said.
“She was full of life, looking forward for tonight. She loved music and she loved this night that celebrated music.”
In the hours after her death, Houston’s songs and albums quickly became top-sellers on iTunes. Fans and celebrities also paid tribute on Twitter.