James died January 20 at the age of 73 of complications due to leukemia at a hospital in Riverside, California.
Etta James, a four-time Grammy winner, was remembered at the memorial service as a woman who broke down both cultural and musical barriers.
Civil rights activist Rev. Al Sharpton described her struggles with poverty and pain while music stars Stevie Wonder and Christina Aguilera sang tributes, according to the Associated Press.
James is perhaps best known for her song "At Last."
Whenever I hear that song, I freeze," Donald Hicks, 67, of Inglewood told the Los Angeles Times. "I even pull over when it comes on."
Aguilera, said she has included "At Last" in every concert she's performed and was inspired by James.
Wonder performed three other of James' songs, including "Shelter In the Rain."
The funeral followed a public viewing of the body at Inglewood Cemetery Mortuary on Friday.