Houston, we have a problem.
Then the singing icon blamed Oprah for the blunder.
U.S. & World
"I'm so sorry. I did 'Oprah.' I've been talking for so long. ... I talked so much, my voice," Houston told the crowd.
The diva apologized to the thousands of fans who lined up in the early morning hours to catch a glimpse of the Grammy Award-winner who was promoting "I Look to You" -- her first album in seven years.
The singer deferred to the audience for the majority of the lyrics, tipping her microphone in their direction as her background singers drowned out fans' cheers.
She ended the concert with fan favorite "I'm Every Woman" and apologized again for her lackluster performance.
"I shouldn't be talking. I should be signing," she said before her final song.
But fans -- who flocked to the outdoor show with T-shirts and signs emblazoned with the singer's name -- didn't seem to mind the shaky performance.
"We missed you Whitney," one fan screamed, according to the New York Daily News.
Houston's rep told gossip website TMZ that the singer was only supposed to perform two songs and that she extended the show.
"She was only ever committed to two songs, so she actually extended the show to the third and fourth songs," she said.
The singing icon's tumultuous relationship with Bobby Brown and her alleged drug addiction have worked to derail her music career.
Houston, who has sold 170 million albums, is slowly stepping back into the limelight and will appear on "Oprah" for the show's season premier on Sept. 14.