Hundreds of R&B and Soul singers have achieved varying forms of success in the music business over the decades, but only a relative few have had lasting success. And among those achieving success, even fewer have been able to have lasting careers -- ones that are either legendary or have the potential to be so. Using a calculation formula that includes vocal creativity, chart-topping songs and albums, awards won, name recognition, songwriting ability and other factors, your R&B/Soul Guide has crafted a list of picks for the best R&B and Soul singers in music history. It includes a few names that might surprise you.
Who: The man who goes by the title Maxwell (he doesn't like to publicly reveal his full name) is an R&B/Soul singer who was raised in Brooklyn, New York and came into prominence during the "neo-Soul" wave of music in the mid-1990s.
When: Active from 1996-Present.
What: His two signature songs are 2009's "Pretty Wings," which he won a Grammy for, and "Ascension (Don't Ever Wonder)," from his 2006 debut album, Urban Hang Suite.
Why: He has the kind of warm, silky voice that makes women (and some men) melt. And his lyrics are complex, intelligent and well thought-out. Unfortunately, he's only released four full albums over the first 15 years of his career, a fairly poor track record for a popular artist.
Who: You know who she is; Beyonce Knowles is one of the most successful and well-known pop-R&B stars of the past two decades.
When: Active from 1998-Present.
Why: She's a one-woman hit factory. Although most of her solo work has been heavy on the pop side, the string of R&B hits she helped sing and write with Destiny's Child stands out. Five years from now, after she's released a couple more solo albums, she'll probably be ranked higher on the list.
18. Whitney Houston
Who: Whitney Houston was one the most popular American pop and R&B singers in the world from the mid-1980s to the mid-'90s.
When: Active from 1985-Present.
Why: Although much of her work leans more toward pop than R&B, her best songs and albums have also been hits on the R&B charts, and she even won a Grammy for Best Female R&B Vocal Performance. Whitney was also a direct influence on many R&B artists that emerged in the '90s, including Destiny's Child.
17. Mariah Carey
Who: Mariah Carey is one of the most successful pop-R&B artists of all time. She helped created the 1990s template of an R&B-pop-rap song mixture that's still utilized by many singers today.
When: Active from 1990-Present.
What: Among her signature R&B/Soul tunes are We Belong Together" (1997), which won a Grammy for Best R&B song, and "One Sweet Day," which features Boyz II Men.
Why: Unlike many singers on the list who started out as R&B artists, then migrated over to pop, it was the opposite for Mariah. And through reintenting herself, she pushed her way toward selling over 200 million albums throughout her career, which is more than anyone on this list except Michael Jackson.
16. Smokey Robinson
Who: Smokey Robinson is one of America's most enduring musical icons. He got his start with vocal group The Miracles in the early 1960 and is still recording new music today.
When: Active from 1961-Present.
What: Most of his biggest hits came during his time with The Miracles, including "Tears of a Clown" and "Tracks of My Tears." But he still releases new music, including a 2009 album called Time Flies When You're Having Fun.
Why: If his career hadn't been derailed in the '80s by drug problems, he'd rank higher on the list. But he definitely deserves placement, not only because of his silky-smooth voice, but because he also helped write hit songs for numerous '60s Motown acts, including the Temptations, Marvin Gaye and Mary Wells.
15. Al Green
Who: Al Green, who's one of the greatest Soul singers and Gospel vocalists ever, was born in Arkansas in 1946 and raised there as well as in Michigan. He's been an ordained minister since a life-changing event (aka the hot grits incident) in 1976.
When: Active as a solo artist from 1967-Present.
What: His signature songs are 1971's "Let's Stay Together" and 1973's "Call Me." Both were top three hits on the R&B and pop charts. But maybe his best known song today is 1977's "Love and Happiness."
Why: Rev. Al made the list based mostly on the strength and consistently high quality of his late 1960s and early '70s work, before he turned to Gospel.
14. Ronald Isley
Who: Ronald Isley has been the lead singer of The Isley Bros. since the band was founded in the 1950s, and in recent years has also been a successful solo artist.
When: Active from 1959-Present.
What: He and his brothers are best known for sexy R&B songs like "Between the Sheets," "Who's That Lady," "For the Love of You" and the R. Kelly-produced "Contagious."
Why: Very few people in music history has had hit songs in six different decades, but Ronald Isley is one of those people. His distinctive, silky smooth voice has easily withstood the test of time and is one of the reasons the name Isley is practically synonymous with R&B.
13. Diana Ross
Who: Diana Ross first found success in the 1960s as a member of girl group The Supremes, then achieved ever greater heights as a solo artist.
When: Active from 1961-Present.
What: Her biggest solo hits include 1975's "Theme from Mahogany (Do You Know Where You're Going To)" and a 1978 duet with Michael Jackson, "Ease on Down the Road." Both songs were from the soundtracks of movies she starred in: Mahogany and The Wiz.
Why: Diana was the original female artist to cross over from singing into acting. And a movie loosely based on her life with The Supremes, Dreamgirls, helped two other well-known singers, Beyonce and Jennifer Hudson, become huge movie stars.
12. Ray Charles
Who: Ray Charles, whose nickname was "Genius" due to his musical talent, was not only a Soul music pioneer, but also R&B and Country.
When: Active from 1949-2004.
What: His most famous hits include "I Got a Woman," "The Night Time (Is the Right Time)," "Hit the Road, Jack" and "Georgia On My Mind."
Why: Despite being blind from the time he was 7, Ray managed to create a long string of hit R&B/Soul songs and albums over more than five decades, plus also help integrate Country music by releasing two Country & Western albums.
11. Sam Cooke
Who: Sam Cooke was one of the most popular singers of the late 1950s and early 1960s. Between 1957 to 1964, he had 20 top 10 singles on the Billboard R&B singles chart.
When: Active from 1945-1964.
What: Among his legendary hits are "Chain Gang (1960); "Cupid" and "Twistin' the Night Away," both in 1961; 1963's "Another Saturday Night;" and the 1964 civil rights anthem "A Change is Gonna Come."
Why: Sam Cooke possessed one of the smoothest, most distinctive voices in music history. Many of the artists who came of age in the 1960s partially owe their success to Sam opening the door to mainstream music at a time when black artists hadn't been readily accepted.