LOS ANGELES — Hundreds of Etta James' friends, fans and family gathered Saturday at a Los Angeles-area church to remember the legendary rhythm and blues singer who died this month.

Mourners at James' funeral are expected to include entertainment luminaries, with both Stevie Wonder and Christina Aguilera scheduled to perform. Aguilera will sing the song that James made famous, "At Last," while Wonder will perform with the church's choir. The Rev. Al Sharpton will deliver the eulogy.

James died Jan. 20 at age 73 after battling leukemia and other ailments. She was most famous for her rendition of "At Last," and in her decades-long career, she became revered for her passionate, soulful singing voice. Her version of the song has become an enduring anthem for weddings and commercials.

Perhaps most famously, President Barack Obama and the first lady danced to a version of the song at his inauguration ball.

"Etta James was a pioneer. Her ever-changing sound has influenced rock and roll, rhythm and blues, pop, soul and jazz artists, marking her place as one of the most important female artists of our time," Rock and Roll Hall of Fame President and CEO Terry Stewart said after her death.

James won four Grammy Awards, including a lifetime achievement honor and was inducted in the Rock and Roll Hall of Fame in 1993.

She scored her first hit when she was just a teenager with the suggestive "Roll With Me, Henry," which had to be changed to "The Wallflower" in order to get airplay. Her 1967 album, "Tell Mama," became one of the most highly regarded soul albums of all time, a mix of rock and gospel music.

Over her lifetime, James battled adversity, including a turbulent upbringing and drug addiction.

She rebounded from a heroin addiction to see her career surge after performing the national anthem at the 1984 Olympics in Los Angeles. She won her first Grammy Award a decade later, and two more in 2003 and 2004.

She is also an inductee into the Rock and Roll Hall of Fame.

James is survived by her husband and two sons.