Singers Mariah Carey, Usher and Jennifer Hudson will mix with R&B veterans Smokey Robinson, Lionel Richie and Stevie Wonder while sports stars like Kobe Bryant and other celebrities were expected at the public farewell to the singer who died suddenly on June 25.

A fleet of black vehicles took Jackson's parents and siblings to the cemetery. The gold-trimmed casket was later carried off in a hearse to the Staples Centre sports arena where the memorial show was being held.

Some 18,000 fans and friends have tickets for the Staples Centre event and a nearby, overflow theater for a two-hour ceremony.

Jackson, 50, died after suffering cardiac arrest in his rented Los Angeles mansion during rehearsals for a 50-show series of comeback concerts in London after a fallow period in his singing career.

Police estimate more than 250,000 people would gather outside the arena to say farewell to the 'Thriller' singer and one-time member of Motown legends the Jackson 5, who was 50 years-old when he died.

Outside the Staples Centre, fans crowded the sidewalks and vendors sold King of Pop t-shirts for US$10 (S$15), as well as posters, necklaces and white sequined gloves that became Jackson's trademark.

'This is certainly a momentous occasion that is probably as big, if not bigger than, when Elvis (Presley) passed away,' said Steve Howard, a resident of Glendale, California, who won a ticket in an online lottery.

'The impact he had on American music and world music crossed all boundaries,' said Mr Howard.

Tuesday's memorial will focus on Jackson's immense musical achievements, which largely preceded a darker side of the singer's life, including his humiliating 2005 trial and acquittal on charges of child sex abuse. -- REUTERS