Etta James, Requiescat in pace.

From ABC News:

Etta James, 73, Dies of Leukemia Complications

Blues singer Etta James, who is most famous for the hit song "At Last," has died from complications of leukemia, her friend and manager Lupe De Leon confirmed. She had been diagnosed with chronic leukemia in January 2011.

James died this morning at Riverside Community Hospital with her husband and two sons by her side, De Leon said.

Click here to see photos of Etta James through the years.

Court records show the 73-year-old entertainer also suffered from dementia and kidney failure. She had been under the 24-hour care of Dr. Elaine James, who is unrelated.

James was born in Los Angeles to a 14-year-old mother and an unknown father. She was brought up by a series of caregivers and began taking vocal lessons at the age of five through her local Baptist church.

James became a gospel prodigy and began singing with two other girls in a doo-wop trio called The Peaches in San Francisco. At 14, James met bandleader Johnny Otis, known today as the "Godfather of Rhythm and Blues." Otis produced James' first hit with The Peaches, called "Roll With Me, Henry" (which was later renamed "The Wallflower"). The song was released in 1955 and soon reached No. 1 on the R&B charts.

Following the success of "Roll With Me, Henry," James left The Peaches and toured with singer Little Richard and guitarist and singer Johnny Watson. Her first major solo hit, "All I Could Do is Cry," reached No. 2 on the Billboard R&B Chart in 1960.

In 1960, James signed with Chess Records and recorded "At Last" a year later. In 1968, she released the album "Tell Mama," which included the song "I'd Rather Go Blind." It became an instant hit, as did the album's title track. In 1962, James recorded the hit song "Something's Got A Hold of Me," sections of which were used this year in rapper Flo Rida's song "Good Feeling."

"She is so evocative and provocative as an artist. She sang songs from the heart," Billboard magazine editor-in-chief Danyel Smith told ABCNews.com today. "It's not anything that anyone can copy or emulate but it has definitely set the bar really high as something to strive for."

Smith said that artists from Keisha Cole to Ciara to Beyonce Knowles have all been influenced by James.

Beyonce, who portrayed James in the 2008 movie "Cadillac Records," posted a statement about James' death on her website today:

"This is a huge loss. Etta James was one of the greatest vocalists of our time. I am so fortunate to have met such a queen. Her musical contributions will last a lifetime," Beyonce wrote. "Playing Etta James taught me so much about myself, and singing her music inspired me to be a stronger artist. When she effortlessly opened her mouth, you could hear her pain and triumph. Her deeply emotional way of delivering a song told her story with no filter. She was fearless, and had guts. She will be missed."

James battled a heroin addiction in the 1960's and 1970's. James had several legal problems relating to her addiction, including being accused of heroin possession, cashing bad checks and forgery. In 1974, after being in and out of rehab for over a decade, James was sentenced to drug treatment instead of serving time in prison and spent 17 months in the hospital. In 1988, at the age of 50, James returned to treatment at the Betty Ford Center in California.

James' tumultuous life was reflected in her on-again, off-again appearance on the Billboard charts, Smith said. James' signature song "At Last" went to No. 2 on the Billboard R&B chart and peaked at No. 2 on the Billboard Hot 100 chart.

"Our charts tell the story but it really is bigger than the charts. It's bigger than the Grammy's and it's bigger than everything," Smith said. "She just conveyed emotion from the bottom of her gut, time and time again."

James' career made a comeback in 1989 with the album "Seven Year Itch." Four years later, she released "Mystery Lady: Songs of Billie Holiday" as a tribute to her idol. James was awarded her first Grammy for Best Jazz Vocal Performance, for that album in 1994.

Throughout her career, James has released 30 albums and 58 singles. She has explored the musical genres of gospel, rock and roll, rhythm and blues, and jazz.

"That sound…it's so deceptively simple. It's so true and of the heart and there's not a lot of orchestration or production," Smith said. "It's just about maybe one or two, at most, instruments and it's about somebody voicing longing and, a lot of times, pain and the tough side of love."

James was inducted into the Rock & Roll Hall of Fame in 1993, the Blues Hall of Fame in 2001, and the Grammy Hall of Fame in 1999 and 2008. In 2003, James received a Grammy Lifetime Achievement Award. She was awarded six Grammys and 17 Blues Music Awards, and was named No. 22 on Rolling Stones' 100 Greatest Singers of All Time.

Today, the Recording Academy released a statement about the "dynamic legacy" James has left behind.

"She will forever be remembered for her timeless ballad, 'At Last,' and a powerful voice that will echo around the world for generations to come," the statement said. "We extend our deepest sympathies to her family, friends, fans and all who have been stirred by her soulful songs and passion for music."

James is survived by her husband, Artis Mills, and their two sons, Donto and Sametto.