At 3:45 p.m. yesterday, Paul Simon stood at a pay phone in the lobby of Howard University's Blackburn Center and got the good news. His New York office informed him that he'd been nominated for four Grammy Awards for his album, "Graceland," which just topped the 1 million sales mark this week.

A few minutes later, Simon walked into Gallery Hall in the same building and got the bad news, delivered by a less-than-pleased audience of about 40 Howard University students who criticized him openly and angrily for defying a U.N. ban on performing in South Africa by recording the album using South African musicians and singers.

It was Simon's third stop in his voluntary lecture tour of college campuses, which precedes his musical tour slated to begin next month in Europe (the tour is scheduled to arrive in Washington in March). Recently, he held informal meetings with students at UCLA and New York University to talk about the creation of "Graceland" and express his own concerns over the controversy that has ensued.

The principal accusation by the Howard students was that Simon violated a U.N. ban on performing in South Africa, which was imposed in 1980, in support of the boycott of the high-paying South African resort, Sun City, by American and British recording artists. "I was offered to play Sun City as a solo act and with Simon and Garfunkel," Simon explained. "I turned it down, and we turned it down. When I went to South Africa {to work on the album}, I in no way thought I was in defiance of the cultural boycott. The boycott is aimed at performing, and in fact, that is the definition of it. Since nobody had gone to South Africa to work with black musicians or deal with the black culture, it became an area available to discussion. Some people said, 'Well, you shouldn't have gone.' Some people, many people, said, 'You were right. You brought the music out.' "

Some of the students supported Simon's action. "I saw this as a way for him to improve his own music and for the American public to find out about the great talents of black artists in South Africa," said Daniel B. Sparks, a history major, who called Simon "a consummate artist."

But most took issue with Simon. "The concept, I like," said Howard senior Mpho A. Tutu, 23, an engineering student and the daughter of Nobel Peace Prize winner Archbishop Desmond Tutu. "I have my reservations because of the ban and where the line is drawn. Once you start to blur the lines, things get awfully smudged." Tutu left her seat early in the meeting and did not appear to return.

"How can you justify taking over this music?" asked Mark C. Batson, 18, a sophomore pianist and music major. "For too long, artists have stolen African music. It happened with jazz. You're telling me the Gershwin story of Africa. 'I'll go there, I'll listen to the stuff, and I'll culturally diffuse it.' You did not go to South Africa. {The musicians} took you to some places, and they showed you some things, but you were not there, because if you were, you would not be alive."

"I went as a musician, and I interacted with other musicians," Simon responded crisply. "It's true there is another level to this story, but this is a beginning, a sincere beginning. I tried to introduce this music to people who never heard it before. Sincerity doesn't seem to be held in high regard.

"I'm here," he continued. "I'm listening. I respond the best I can. At least I'm into dialogue. I have always intended that this music be used to serve the African people. I came down here because I want to hear what's being said."

Simon pointed out that he gave songwriting credits and paid triple American scale to the South African musicians for their studio work. His upcoming tour will feature Ladysmith Black Mambazo and Stimela, two of the African bands that recorded nine of the 11 tracks on his album with him. South African trumpeter Hugh Masekela and South African folk singer Miriam Makeba will also perform on the tour, which is scheduled to begin in Europe Feb. 1, return to the United States in early March and then go back to Europe, where it will end in April