The minute Secretary of State Cyrus Vance mentioned the name Andrew Young in his speech yesterday morning, the crowd at the NAACP convention burst into cheers. Then the microphones started squealing and hissing before sputtering to a dead silence.

"It's the KKK," someone yelled from the audience. In the 15-minute interim, Vance held an impromptu receiving line. Some in the crowd began to sing songs associated with the civil right movement, and Vance even tried to join in on a few choruses of "Lift Every Voice and Sing." He didn't know the words so he faked them. Then the mechanical difficulties were fixed and Vance started the same sentence over again. This time everyone stood up and cheered.

The 68th annual conference of the nation's oldest and largest civil rights organization was a convention that swirled with sentiment, tension and hurried fun. But all the action wasn't in the press conferences and on the platform. Some of the sights and sounds.

"Amazing Grace," the voices at the James Cleveland concert soared. All of a sudden a nun, Sister Kathleen Crowley, fainted in the third row, soprano section. "Amazing Grace," the 200 other voices went on.

Sen. Thomas Eagleton (D-Mo.) had been scheduled to appear at a tribute to Roy Wilkins before it was known he was a co-sponsor of an anti-busing amendment. He accepted on the condition that the Senate would not be in session that night. At the precise hour the honors and praises for Wilkins were being read in St. Louis, Eagleton was watching his amendment being passed by the Senate. The next morning, Margaret Bush Wilson, chairman of the NAACP Board, called for President Jimmy Carter to veto the appropriations bill for HEW and indicated she would gather forces to work against Sen. Eagleton's "repressive measure." There was a lot of gloom over the backlash among "old friends."

The teenagers from Alabama were selling banana yellow T-shirts with Roy Wilkin' picture on them. The National Student Coalition Against Racism was distributing leaflets in support of the NAACP.

And Prince John, a representative of what he claims are 3.5 million black black gays, distributed an open letter to the convention that said: "You very well know how hard we had to fight just to come this far."

A few aisles away in the exhibitors' hall was a small, almost inconspicuous booth from the Central Intelligence Agency. As people walked by, they stopped, walked back and talked to the three people who were operating the booth. "Yes, everyone laughs at first," said one young black at the booth. "But also everyone asks about jobs."

Barbara Morgan, one of the Washington delegates, was sitting in a workshop on political action. "I had a good position in Atlanta," the speaker was saying. "And when I found another job opportunity the person who would succeed me was a white person. So I decided just to take leave who would succeed me was a white person. So I decided just to take leave from my job so the person second in line, a black, would have time to build up his seniority. And when he had advanced up the scale, I called them back and said I was quitting so the brother could step into my place." Taking notes and smilling at the new kind of tactic, Morgan said, "Wow, he didn't have to really sell his soul. That's a beautiful way of dealing with the new kinds of discriminations we're finding today."

In a way the convention was a public accommodations test. The 8,000 delegates were the first group to se the $36-million St. Louis Convention Center. And because the hotel connected with the center had not been completed some of the delegates had to stay 35 miles away.

When Edward Ghee, 50, and Albert Ross, 47, two delegates from southern Virginia, sat down for lunch, they talked about how hard it was to get a loan for home improvements. "I feel white folks are turning back the clock. I just feel it in the attitude in the streets," said Ross.

"No to racism from Boston to South Africa," said the buttons the youths from the Greenwich Village NAACP chapter were handing out as the crowd moved into the auditorium where Alex Haley would receive the prestigious Spingarn Medal for "Roots". Hours later, Haley was grabbed by Jackie Berry, 16, of Chicago for an autograph, and Berry afterwards ran down the hall screaming, "Alex, I saw him, Alex Haley."

"NAACP, join us. Join us, NAACP."

The pickets, a group of local young blacks and whites dressed in jeans and T-shirts, marched in front of the new convention center where the group was meeting. They wanted the organization to help in the investigation of the shooting of a local minister.

His eyes were tired but his voice was still strong and he looked out over the audience that had come to hear his views on the prison system. And Clarence (Willie) Norris, the only surviving member of "The Scottsboro Boys," who spent 15 years of his youth in jail and received a pardon from the state of Alabama last year, said, "Some people speak of freedom but don't know what it means. You have to depart from it fora time to appreciate it."