At 10 a.m. in Clyde's Omelette Room, William King, Thomas McClary and Milan Williams -- half of the Commodores -- were splitting their attention between business and breakfast.

Like fraternity brothers (they came together in 1969 as undergraduates at Alabama's Tuskegee Institute), they laugh often and easily. They finish each other's sentences, and while one is concentrating on answering a question, the other two sneak their hands in to clear off the breakfast plate.

The six-man pop group -- appearing at the Capital Centre tonight as part of their 96-date national tour -- is among the top 10 acts in the music business and a miracle of longevity. Their latest album is near the top of the charts, and the group will make close to $10 million in 1980. Despite the breakfast-table horseplay, it's not hard to see why.

A mention of radio spots brings a gufaw. Election years make for tight radio advertising time. As November approaches, radio spots are usurped by political campaigns, and spots advertising concerts and albums become increasingly rare. "But we beat the political people to the punch," chortles Williams, 31. "Course, we programmed time way back at the beginning of the year. And they've come in right behind us to see if we'd give up some of the time." A big laugh goes around the table.

The group's legendary caution has kept them afloat in rough business waters. "We look through the water and see where the fish are first," says King, 31. "That's kept us out of trouble."

The Commodores don't rush into anything. They waited two years after signing with Motown to release their first album. And despite their reputation in the music business, they've continued to live in Tuskegee, a college town of 11,000 with no movie theater, no elevators, two restaurants and three streetlights. "It's a unique, wonderful little town," King insists. "It serves as a rest place for our heads. And the students are a wonderful sounding board. We get knowledge traveling around the country and the world. At some point, we need to come back and gather the knowledge and translate it into our music."

At home the members of the group stay in touch over a CB network. King's handle is The Red Baron. Williams is Captain Quickdraw and McClary, 30, clocks in as Mr. Magoo. "I have my own family," says Williams, surveying a table cluttered with dishes that have been scraped clean. "But this is my family, too. We are married to each other."

In a 11-year career that has yet to see a personnel change, the Commodores have often had the last laugh when it came to the business of show business. Three of the group were marketing or business majors at Tuskegee. As a sophomore, Williams saved $1,200 from gigs, bought a house on a 90-by-310 foot lot, then sold it during his junior year and promptly bought two larger lots. The same strategy has applied to their 10 albums, the most recent of which, "Heroes," sits comfortably in the top-10 sales charts. Their first three albums went gold, the next three went platinum, followed by double platnum and triple platinum plateaus.

And at a time when many major groups find it difficult to fill arenas, the Commodores are kicking off a national tour expected to put them before a million and a half people. That's a far cry from 1969, when King started working on a combination thesis and game plan dealing with the challenges facing black entertainers (all this before crossover appeal started to blur the lines in the mid-'70s).

"Everyone was very inquisitive about the industry," recalls King."They wanted to know why the Beatles, Led Zeppelin, etc. could draw 20,000 people into an auditorium and it took nine R&B acts to get 4,000 people into a neighborhood theater. To us, that didn't set right, because we felt our music was just as good."

King spent 2 1/2 years puting together a 270-page paper. By the time the group's first album came out in 1973, they had already built up a massive audience by touring the world several times. Their first hit, the instrumental "Machine Gun," was played for years on nightly television in Nigeria -- right after the national anthem. As the first album turned gold Stateside, it did likewise in Japan, the Philippines, Nigeria and Australia.

Over the years, the Commodores also developed an extensive crossover appeal through pop hits like "Three Times a Lady" and "Sail On." Their audience today is racially balanced, though, McClary says, "you don't ever get so far out there that the people you started with can't indentify." Indentifying is one reason the Commodores, unlike almost every other group of similar stature, were visiting Washington a week before their concert. Sleeping through the night as their well-appointed tour buses rolled north through the Carolinas, the group checked into the Hyatt Regency at 4 a.m. and started the first of a half-dozen radio and television interviews at 9 a.m. The other three Commodores (Ronald LaPread, Walter Orange and Lionel Richie) were working the Midwest.

"It's what we do," says King. "It's what we're all about." The group's financial acumen -- translating into several corporations with a staff of two dozen and holdings in real estate, African art and rare coins as well as stocks -- gives the Commodores an unusual amount of career control. Before they had ever recorded, the group formed Commodores Entertainment Corp., with divisions for licensing, management, publishing and sponsorship (as in their current commercials for Schlitz). "We're serious businessmen," King points out soberly. "The music is the catalyst but the business is where we really are."

And yet, they say, some people still think that, just because they're musicians, they can be taken. "'Here, let us take care of your money...just give us power of attorney so we won't even have to bother you...'" Milan Williams feigns a sincere, concerned air and then joins the others in peals of laughter. "You won't have to bother me at all, 'cause I'll probably be dead with a heart attack."

Among the group's possible future ventures are film appearances and solo albums. A brief appearance in "Thank God It's Friday" followed a scene in another movie that never made it off the cutting-room floor. Recently they completed the theme track to "Underground Aces," an action film due for fall release. Remembering it, all three shake their heads. They saw the movie four times -- first as a six-hour rough, then in increasingly condensed versions of 3 1/2, 2 1/2 and 1 1/2 hours, with no music, no ending and a minimal audio track. "And no popcorn," adds McClary. From all that, they had to summarize the plot into a song that would be commercially acceptable on the radio whether anyone had seen the film or not. "It was," King chooses the word carefully, "fun."

But who's worried? Their show at the Capital Centre tonight is expected to sell out with walk-up sales, and they seem invulnerable. Outside of Clyde's, the group's two limousines surround a fire hydrant.A tow truck arrives -- and takes away an economy car parked directly in front of them. Inside, the Commodores keep laughing.