They had a lot in common, both from small towns, both ambitious.

But Leontyne Price, Jimmy Carter said yesterday at the third in a series of Sunday afternoon White House concerts, outdistanced him in one respect.

She made it to the White House 11 years before I did."

The Metropolitan Opera star's return engagement for a national audience on public television pointed up something she has been emphasizing throughout her career, the president noted.

"What we are trying to do is what Leontyne Price has always tried to do: to convince the American people that opera is not just a luxury for a few, but it a thing of beauty to be enjoyed by everyone."

Her first performance at the White House was for the late Aldo Moro, then president of the Council of Ministers of the Republic of Italy, in 1965 when she received a Presidential Medal of Freedom.

Price's performance won raves.

"Fantastic," said Zubin Mehta, musical director of the New York Philharmonic. "She didn't sing one ugly note for the whole hour."

Charles Schutze, chairman of the Council of Economic Advisors, also applauded vigorously. Schultze wasn't talking about what will be in the president's forthcoming anti-inflation message. "We'll put it to music," he quipped. His choice of composers and opus was Berlioz' "Symphonic Fantastique," which horrified an eavesdropping music critic.

The Berlioz work is "much too elaborate," requiring a huge orchesta, an undertaking that "hardly pared down to essentials" at a time of inflation fighting, the critic said. President Carter burst out laughing later when informed of Schultze's choice for setting his anti-inflation message to music. But he had his own thoughts on who should compose it and who should perform it.

"How about Willy Nelson to compose it," asked Carter, "and Miss Price to sing it?"

As for Price, she thought "that sounds very encouraging." She said she was "disarmed" by both Jimmy and Rosalynn Carter - "the gentleness of the meeting was indescribable." She had voted for him in 1976 and said she saw no reason why she shouldn't again.

The crowd of 230 included the singer's brother, retired Army Gen. George B. Price and some old friends, the Chisholm family, from Laurel, Miss., where the Prices grew up.

But price seemed reluctant to spell out her relationship with the Chisholms beyond "why don't we just say we are friends?" She appeared determined to set the record straight about who helped her get where she is.

"The people who really helped us were our parents, Mr. and Mrs. James F. price. They stand out as helping us, if you don't mind. It's not everybody who in one fell swoop has an opera singer and a brigadier general." Then, laughing a little she added, "Notice how modest 1 a.m."

In the Blue Room, Mrs. Alexander Chisholm and her daughters tried to shun attention. It was not their afternoon, one of them said, it was a tribute to Leontyne Price. But Mrs. Chisholm acknowledged that she had helped financially when price won a scholarship to study at the Juilliard School of Music. The Association had been a natural one, she indicated, since Price's aunt had worked for Mrs. Chisholm's mother for 50 years in Laurel and the singer's parents ahd been married in the Chisholm family garden.

The guests were a cross section representing the government, the arts, business, labor and the media. Secretary of State Cyrus Vance was optimistic, saying he "would think" Carter will go wherever the Mideast peace treaty is signed. Zubin Mehta stood transfized as he listened to the Marine band playing deny that he would enjoy conducting them.

There were strawberry and pecan tarts, marinated shrimp, steak tartare and champagne for everybody. But President Carter didn't linger after the receiving line ended. He was off to spend the holiday at Camp David, and out on the South Lawn his means of transportation awaited him.

"How tacky to have a helicopter parked on your lawn," giggled a couple of first-timers who didn't really think it tacky at all.