Once marginalized, R&B enjoys mainstream reign.

These days, it's not unusual to find Alicia Keys, Chris Brown, Ne-Yo and other contemporary R&B artists residing on the U.S. singles chart -- especially in its upper echelons. But that wasn't always the case.

Just ask Jerry Butler, a founding member of the Impressions. When the Hot 100 singles list debuted in 1958, the legendary Chicago soul group was breathing rarefied air as its "For Your Precious Love" settled in at No. 15. The single would eventually peak at No. 11 on the chart (and No. 3 on Billboard's Most Played R&B by Jockeys chart).

"It was difficult getting R&B records into major department stores," recalls Butler, nicknamed the Ice Man for his soulful, smooth-as-ice vocals. "Then there were (white) pop singers covering R&B hits, like Georgia Gibbs (LaVern Baker's "Tweedlee Dee," Etta James' "The Wallflower") and getting wider exposure and sales than black acts. That was the way things were in those days."

Before legendary producer Jerry Wexler, who died in August, helped coin the term "rhythm & blues" for Billboard in 1949, black singles' chart progress was chronicled in the magazine under the climate-revealing list titles Harlem Hit Parade (debuting in 1942) and Race Records (1945). But thanks to R&B groups like the Impressions and the Platters -- who ruled the top of the Hot 100 in 1959 for three weeks with "Smoke Gets in Your Eyes" -- things slowly began to change.

Peaking at No. 6 on the Hot 100, Ray Charles' "What'd I Say" was a portent of things to come. During his career, Charles claimed 12 top 10s on the chart, including three No. 1s. Then an upstart label by the name of Motown began flexing its R&B/pop muscle. Its precursor, Tamla Records, notched its first hit with the Miracles' No. 2-peaking "Shop Around" in 1960. Four years later, labelmates the Supremes began their march to ultimate girl group glory with the first of 12 No. 1s, "Where Did Our Love Go."

With increased radio airplay and retail accessibility, R&B continued to raise its mainstream profile. Among the acts upping the ante were James Brown, Aretha Franklin, Sly & the Family Stone, the Jackson 5, Isaac Hayes, Lionel Richie and Whitney Houston.

Then Boyz II Men drove home R&B's mainstream potential in a big way. The Philadelphia quartet broke the record at the time for most weeks at No. 1 on October 24, 1992, when "End of the Road" notched its 11th week atop the singles chart. In the years since then, the genre has remained a powerful chart presence.

Reuters/Billboard