Ronald and Ernie Isley could complain that the gatekeepers of pop history have not blessed their group with the same legendary status as Marvin Gaye, Aretha Franklin, Stevie Wonder, James Brown and the like. They'd have a pretty good argument. The Isley Brothers are widely believed to be the only act to score hits in the '50s, '60s, '70s, '80s and '90s. Their music has traversed doo-wop, R&B, Motown pop, funk, rock, soul balladry and social commentary. Their anthems include "Shout," the gospel-fied rave-up that charted in 1959 and has become a party standard, the late '60s throwdown "It's Your Thing" and the churning mid-70s rant "Fight the Power."

Yes, the Isleys could gripe — but they don't. They're too busy with their hits in the '00s: this year's smash Eternal album, which entered the Billboard sales chart at No. 3, and the sultry single, "Contagious." (Just to recap: That makes six consecutive decades in which the Isleys have notched hits.) The now-platinum Eternal may be a contender for the best-selling album of the band's illustrious career.

"We've always concerned ourselves first and foremost with doing the music," declares guitarist Ernie Isley. "We're not in control of the media at large. It's somebody else's candy store and they can talk about whatever candies that are in the store. We can't control how our legacy is understood. Besides, we're still sharpening our knife. Britney's our competition, Jay Z's our competition, not Sly (& the Family Stone) and Earth, Wind and Fire. Hanson and the Spice Girls are old school now."

Old school legend or current hitmaker? The Isleys choose the latter, thank you.

Both would be better.

Actually, the Isleys are at the very least semi-legends, or soon-to-be-bona-fide legends. By and large, pundits now agree that they've surpassed James Brown as the most sampled act in hip-hop. Notorious B.I.G.'s "Big Poppa" lifted a hook from "Between the Sheets"; Ice Cube's "Today was a Good Day" used the Isleys' "Footsteps in the Dark" as a foundation; Aaliyah, Da Brat, Coolio, Bone Thugs-n-Harmony, Salt-n-Pepa and others have also drunk from the cup.

The Isleys get mad props from today's hip-hoppers, none more so than R. Kelly, who gave rise to Ronald Isley's mack-daddy alter ego, Mr. Biggs. For his self-titled 1995 CD, Kelly wrote a song with Ronald in mind. The hit "Down Low (Nobody Has to Know)" and its high-profile video unleashed the Mr. Biggs character. Ronald's alter ego then appeared on Kelly Price's "Friend of Mine" remix, a remix of the Isleys' "Floatin' on Your Love" and now "Contagious."

Neither Ernie, 49, nor Ronald, 60, is eager to give Mr. Biggs too much credit for The Isley Brothers' improbable 21st century resurgence. "You gonna sell multi-platinum only if the song is good," says Ronald. "The character doesn't come alive unless the music's there."

Still, the flamboyant Biggs has reconnected the group with a youth audience. Sure, the kids may have danced to "Shout" at their aunt's wedding, maybe heard "Who's That Lady" on their parents' stereo, or one of Ernie's guitar parts in a rap tune. But do they know it as the Isleys? There's a reason Eternal is cumbersomely credited to The Isley Brothers featuring Ronald Isley, a.k.a. Mr. Biggs. As Ernie says, "Four-year-old kids know Ron as Mr. Biggs."

The six brothers Isley were raised in the black middle-class town of Lincoln Heights outside Cincinnati. They worshipped and sang at downtown Cincinnati's First Baptist Church, where their mother was the organist and choir director.

The oldest group of brothers — O'Kelly, Rudolph, Ronald and Vernon — became enamored with church-based R&B stars like Clyde McPhatter, Sam Cooke and Jackie Wilson. Younger brothers Marvin and Ernie, more than a decade younger, were still playing with Tonka trucks. In 1954, Vernon was hit by a car and killed while riding his bicycle. The remaining three brothers stopped singing for a spell, but resumed at the insistence of their parents. The Isley Brothers relocated to New York, where they spun out a couple of doo-wop singles that went essentially unheard.

Their breakout song was something of a risky proposition, and set a chance-taking trend that would last throughout the Isleys' career. "Shout" was a straight-up gospel stomper, a little too much so for 1959. But the song's sheer effervescence made it an R&B hit and middling pop success.

In '62, The Isley Brothers released "Twist and Shout," which reached No. 17 on the pop chart. Two years later, the Beatles' virtual carbon copy became a smash and is now recognized as the definitive version.

Unsatisfied with their record company experiences, the brothers launched a venture unprecedented for black artists in 1963: They formed their own label, T-Neck, named after the northern New Jersey town where they lived.

Seeking a new guitarist, Ronald found one Jimmy James at the Hotel Teresa in Harlem. Real name: James Marshall Hendrix. During his roughly two-year stay with the Isleys, he became a houseguest of the family. "He was playing guitar for the Isleys and I was playing centerfield for little league baseball," says Ernie, who readily admits Hendrix's influence on his playing but also points out that he was not even playing guitar when Hendrix was around. "He practiced more than anybody. I remember the guys going to see this new James Bond movie, Goldfinger — whispering about this character Pussy Galore — and he wouldn't go; he stayed home playing his guitar."

A handful of years hence, when Ernie was in high school, kids would argue about whether Clapton or Hendrix was the preeminent rock guitar god. "They never asked me," Ernie recalls. "And they were blown away when they read in the magazines that Hendrix played in The Isley Brothers and lived in our house."

Although it offered artistic freedom, T-Neck did not deliver hits, so the Isley Brothers did a complete 180 and signed with Motown, a hit factory ruled by iron-fisted owner Berry Gordy. Problem was, the hits did not gush forth for the Isleys at Motown either. Only 1966's "This Old Heart of Mine (Is Weak For You)" climbed the upper reaches of the charts.

Three years later, their efforts at writing stifled by the Motown hierarchy, and tired of the company's toe-the-line image machine, The Isley Brothers asked to be released. "He told us we were part of the family and he'd never stand in our way," Ronald recalls. "We were little fish on the chain out there anyway."

Gordy was not so magnanimous when the Isleys, after reactivating T-Neck, shot to No. 2 with 1969's gritty, resolutely non-Motown "It's Your Thing." Gordy sued. And lost. "It was starting to tumble for him," Ronald says. "That's why he sued us; he knew he couldn't let someone leave Motown and make it. After we made it, the Temptations and other acts started saying, "Let me outta this door.'"

In the mid-60s, Ernie and Marvin started poking around rehearsals. "They'd let me play drums when the drummer was on a break," Ernie remembers. "Then the guy quit. Someone said, "How 'bout Ernie?' My brother Kelly said, "Pleeease, get outta here.' Someone said, "He plays better than that bozo who just walked.'"

So it happened that 14-year-old Ernie Isley played his first Isley Brothers gig in Philadelphia. He also backed Martha Reeves & the Vandellas. "After the show, I stepped through the backstage door and there were like 19 girls sayin', "That's him. That's him,'" Ernie says. "I tell you I wanted to move to Philly right then and there. We were living in Englewood, N.J., at the time. But of course, Cinderella had to go home, back to school."

1973's 3+3 album heralded another seismic shift for The Isley Brothers. Bassist Marvin, guitarist Ernie (who also played drums) and brother-in-law Chris Jasper (on keyboards) officially joined the three older siblings. The younger trio cranked out rhythm tracks with a decidedly more funky, contemporary edge. The rockin' "That Lady" showcased Ernie's extended guitar solos; fluid, Hendrix-inspired and imbued with that little extra scream courtesy of a phase-shifter effects pedal, the sound was an R&B anathema. Ernie's guitar became a signature of the Isleys' sound, which was rooted in Ronald's high, velvety vocals.

The mid-70s proved to be The Isley Brothers' artistic heyday. They unleashed the sinewy funk of "Fight the Power" and the luminescent love ballad "For the Love of You." They transformed Seals & Croft's limp "Summer Breeze" into a sensual soul ballad, similarly recast James Taylor's "Fire and Rain" and gave the rolling funk treatment to Stephen Stills' "Love the One You're With." Having been covered and copied through the years, the Isleys turned the tables by infusing pop songs by white artists with their own brand of soul, and effectively introducing them to the African-American community.

In 1976, as America celebrated its bicentennial and began to emerge from the shrouds of Vietnam and Watergate, The Isley Brothers reached their pinnacle with Harvest for the World. The title track, a song that balanced protest and hope, breezed along on the stripped-down strength of Ernie's 12-string acoustic guitar, bass, piano, drums and handclaps. It was antithetical to the flowery arrangements favored by the surging disco movement.

Over time, the schism between the younger and older brothers widened. Ernie, Chris and Marvin split to form Isley, Jasper, Isley, and scored a hit in '85 with "Caravan of Love."

The ensuing 10 years were lean, tough and full of further change. In '85, the older triumvirate signed a deal with Warner Bros., effectively bringing T-Neck to a close. A year after the release of their debut, the misnamed Masterpiece, O'Kelly Isley died of a heart attack at age 48. Shortly after, Rudolph retired to the ministry. Marvin and Ernie rejoined Ronald in 1990, but the hit-making magic did not kick back in.

Money woes rained down on the brothers. Ronald and Rudolph went bankrupt; their New Jersey mansions were put on the auction block. Marvin, a severe diabetic, left the group, leaving Ronald and Ernie as the last standing. The Isleys' fortunes began to turn with the strong-selling 1996 effort, Mission to Please.

It wasn't until last year, though, that the financial resurgence took full effect. The older Isleys won a $7-million judgment against Michael Bolton for plagiarizing their 1966 song "Love is a Wonderful Thing." (Bolton, in turn, tried to buy the Isleys' song catalogue but was rebuffed by the courts.) And they earned a reported $20-million to $30-million after the issue of Pullman bonds, which are backed by future royalty payments.

Marvin Isley, now a double amputee, sued Ronald and Rudolph for his share in O'Kelly's newly enriched estate. According to the Bergen (N.J.) Record, Marvin, Ernie and Chris Jasper were salaried employees during most of their tenure with The Isley Brothers. Further, attorneys for the older brothers claimed that Marvin and Ernie signed a release in 1991 that excused them from personal debt liability and prevented claims on future royalties. Ernie Isley did not join Marvin's complaint and, in fact, testified against him last year.

Such strife seems less and less relevant in light of The Isley Brothers' most recent show of resilience, the aptly named Eternal. Their importance is not measured just on the charts. The group's influence runs far and wide.

And yet there's that vague, vexing lack of respect for their accomplishments. And there are those other artists with lesser achievements who bask in iconic status. The meteoric Sly Stone, who helped merge the soul aesthetic with the hippie dream, is regarded as something of a deity, even though his career effectively lasted from 1968 to '75.

Perhaps The Isley Brothers are still waiting for their proper due because they never fully chased the crossover dream. They built their fan base within the black community and did not make stylistic concessions to reach a mass audience. And except for their disastrous stint on Motown, they never had the industry clout to thrust them into the limelight. Nevertheless, they garnered broad commercial support in spots — on their own terms — and returned to the open arms of loyal African-American fans in leaner times.

The gatekeepers of pop history, after all, are mostly middle-aged white men. The Isley Brothers have been only on the periphery of their radar. To these legend-makers, dying young is better than growing old; brief spasms of creative activity are better rewarded than longevity. Sooner or later, though — probably sooner — the gates will open and The Isley Brothers will be welcomed into the club of elite pop gods. And don't be surprised if they have a hit album on the charts when it happens.

The Isley Brothers perform at 8 p.m. Thursday, Nov. 1, at Ruth Eckerd Hall. Tickets cost $100 for the first three rows, $60 and $45. Call the REH box office (727-791-7400) or Ticketmaster (813-287-8844 or 727-898-2100).

Contact Associate Editor Eric Snider at 813-248-8888, ext. 114, snider@weekly planet.com.

Eric Snider is the dean of Bay area music critics. He started in the early 1980s as one of the founding members of Music magazine, a free bi-monthly. He was the pop music critic for the then-St. Petersburg...