Family and friends of American pop music icon Whitney Houston are saying their goodbyes to the singer Saturday at a private funeral at her childhood church in Newark, New Jersey.

Celebrities, including music greats, are joining the final tribute at the New Hope Baptist Church, where Houston sang in the choir as a child. Fans showed their love with hundreds of balloons, flowers and cards piled outside the church.

The service for the 48-year-old six-time Grammy award winner and actress comes a week after she was found unresponsive in a bathtub at the Beverly Hilton hotel in California.

A gold-painted hearse transported Houston's casket to the church Saturday morning, a day after her family attended a private viewing of her body at a Newark funeral home.

Her mother, Cissy Houston, and daughter Bobbi Kristina Brown were joined at the viewing by a host of relatives, including singer Dionne Warwick, Houston's cousin. Her mentor, music executive Clive Davis, also was there.

Warwick introduced a host of soul, gospel and pop music greats from the past and present, including Alicia Keys who performed the song Prelude to a Kiss.

Houston's mentor, Clive Davis told mourners, “You wait for a voice like that for a lifetime,” while her co-star in the movie, Bodyguard, Kevin Costner, asked mourners to “remember the sweet miracle of Whitney.”

Music legend Stevie Wonder was among the planned performers at Saturday's invitation-only service. Houston's ex-husband, singer Bobby Brown, put in a brief appearance at the service but close family friend, Aretha Franklin, was unable to attend because of health issues.

The private church service was broadcast live on the Internet and TV.

Houston will be buried next to her father, John Russell Houston Jr., at a New Jersey cemetery.

The cause of her death is not expected to be known for several weeks, pending toxicology results.

Houston sold more than 170 million albums, singles and videos, making her one of the world's best-selling artists. But in recent years, her career faced ups and downs as she struggled with drug and alcohol abuse.