The azan, the Islamic call to prayer, echoed along Embassy Row from loudspeakers set outside the mosque at 2551 Massachusetts Avenue NW. It was a hypnotic wailing that on a recent Friday, the Moslem holy day of Jumada, lured scores of worshipers for a midday sermon and prayer.

Among those who arrived was Muhammad Shakur, a slim, languid bookstore employe dressed in a caftan and kufi. He carried a copy of the Koran. He had journeyed to the mosque by Metro bus from his Northeast Washington home and was greeted with handshakes at the gates by other Moslems.

"As-salaamu alaikum," they said, smiling. Peace be with you.

Most of those gathered at the mosque were Middle Easterners, but many others were just like Shakur--black Americans from Washington, D.C., disaffected Baptist and Methodist men who had found better living through Islam. The congregation was almost entirely male.

"I had been away from the church for about 10 years before I decided to check it out," said Shakur, 34, the son of a D.C. Environmental Services employe. "Religion no longer seemed relevant, or I figured I could do without going to church, but that was not true at all. I realized we need something spiritual in our lives. After being invited to the mosque by a friend, I came to see that there is a reason why Islam is the religion of Africa and black people around the world."

He flipped open his Koran to guide him through a recitation, "Allah says: 'O ye who believe. Retaliation is prescribed for you in the matter of the murdered; the freeman for the freeman, and the slave for the slave, and the female for the female. And for him who is forgiven somewhat by his (injured) brother, prosecution according to usage and payment unto him in kindness. This is an alleviation and a mercy from your Lord. He who transgresseth after this will have a painful doom.'"

Shakur snapped the book shut, pursed his lips and glinted his eyes, knowingly.

"You better get on board, brother," he warned. The tone was kindly. Sort of.

According to leaders in Washington's Islamic community, black men in growing numbers are attending services at mosques around the city, taking time to study the Koran and incorporating the five pillars of Islam into their daily lives.

While black Americans have had a longstanding interest in Islam, their earlier involvement was mainly through such groups as the Nation of Islam and the American Muslim Mission-- the former claiming that Elijah Muhammad was a prophet and the latter contending that black people are superior to whites. These two concepts offend Islamic purists, who believe no man stands above another and that Mohammed was the last of the prophets.

Even so, the labors of the two organizations familiarized many a black neighborhood with the word "Islam." In time the fundamentals of this worldwide religion would capture the imagination of thousands in Washington.

There are now about 20,000 to 30,000 Moslems in the Washington area, but just how many of them are black Americans is unknown. However, increases in attendance by black Americans continue at the area's mosques--the Islamic Center, the Community Mosque and at Moslem student centers at universities around the city.

"There has been a substantial increase in black Americans turning to Islam--and it increases every day," said Tarik A. Abul-Qasim, who has been a leading figure in the Moslem community here for 20 years. "Black people are by nature very religious. But black men need an outlet for their masculinity. In a church, they become nonthinking members with a preacher interpreting everything for them.

"When I became a Moslem, I was an altar boy in a Catholic church, but I was afraid of vampires," Abul- Qasim said. "Once I learned about Islam, I realized there is nothing to fear, not even death. There is nothing metaphysical or mystical about Islam."

More than anything else, it was this inability of the Christian Church to deal with the problem of where the black man fits in America-- as well as the universe--that those interviewed cited as the reason for their conversion. In times of crisis, they said, Christianity proved contradictory and too hard to comprehend as a source of solace.

"See, I was raised a Baptist and in church there were some principles that you were supposed to live by but some of the people weren't living by them," said Muhammad Abdullah Mustafa, 24, a digital electronics student at the University of the District of Columbia. "This would more or less turn you off if you had some sincerity about living for the Creator."

Mustafa, who has been a Moslem for nearly two years, says he's saving his money in accordance with Islamic doctrines so that as soon as possible he can make his hajj, the pilgrimage to Mecca expected of all devout Moslem males. He spoke of feeling "in harmony" with the world, and no longer saw it as "black and white."

His mother, Louise Blake, a retired government worker who lives in Northeast Washington, stands by her son even though he has rejected the Baptist faith by which he was raised.

"This Islam sounds like true religion to me," she said. "They don't believe in smoking dope, drinking liquor and no adultery. I say we could use more teaching like that. I'd rather see a boy into something that means something than be on the street smoking dope."

"It's not that I don't believe Christianity is a true religion," Mustafa said. "But Islam makes me adhere to principle better. It's clearer. As a man, it gives you responsibility; it says you must take action and that all men are leaders."

Black American Moslems have been involveddon both sides of the controversy at the Islamic mosque on Massachusetts Avenue that led to the board of directors' closure of the house of worship March 5. The dispute centers on the question of whether the imam, the congregation's spiritual leader, should be appointed or elected. There is historical precedent to support both claims. Despite the differences the disputants have over this religious rule, however, they are in accord as the source of authority for Islam.

"What's so hip about Islam is the Koran," said Abdul Ahmed, 34, who lives on Columbia Road and was a Baptist until four years ago. "The Koran is the word of God. It's not like the Bible, which has been interpreted and reinterpreted through the years. I grew up on a King James Version. Now who was that man?"

For Ahmed and the others who attend services at the mosque, the ousted imam Muhammad Asi would explain that there is no man in authority--only Allah. As the congregation knelt inside the cavernous room that Friday, their shoes stacked on shelves outside, Asi told them that God is the Lord of the universe.

"The sun, the moon, the earth and all other heavliy bodies are thus 'Moslems.' So are the air, water and soil and all the living things like the insects, birds and mammals of the animal world as well as the shrubs, trees, vegetables and the fruits of the plant world."

Says Asi, "Everything is Moslem for they all obey God almighty by submitting to His laws."

For the Moslem adherent to pure Islam, there is only one God--in Arabic, Allah, "the God." According to knowledgeable Moslem believers, Allah revealed His will to his messenger, Mohammed of Mecca, in the seventh century A.D. These revelations are written in the Koran.

"Islam" is an Arabic word meaning submission, surrender and obedience. Muslim, or Moslem, means one who submits. Both Islam and Moslem, in turn, are derived etymologically from "salaam," peace.

The practice of Islam is based on five pillars:

First, a one must profess that there is no God but Allah.

Second, one must pray five times a day--at dawn, noon, acefternoon, sunset and night.

Third, one must fast for one month every year at Ramadan. This means not only o food or drink from sunup to sunset, but no sexual activity or fighting either.

Fourth, one must make zakat, a charity payment to the poor amounting to 21/2 percent of one's annual income.

Fifth, one must try, health and finances permitting, to make the hajj--the pilgrimage to Mecca--at least once in a lifetime.

Of the five pillars, it is the hajj that is virtually indescribable, an electrifying experience for those who have made it.

"I had dreamed of what it was like, but that was nothing compared to being there, in the midst of over 2 million people from all over the world," recalled Abdul Ali, 36, who was born in Southeast Washington and spent $2,000, half of his life savings, to make the trip to Saudi Arabia in 1975. He stayed for nearly a month, attending Idul-Adha, "The Feast of Sacrifice," which commemorates Abraham's consenting to sacrifice his son.

"That trip changed my life," Ali said. "I had never been out of the States. Everybody was wrapped in white cloth, on their knees, everybody from kings to peasants, with their face on the same earth as one. See, it's possible to bring everybody together through Islam, I believe."

According to Cain Felder, a professor of religion at Howard University, there is a pattern to the fluctuations in interest in Islam within the black community. During the 1960s, he says, there was a rise in black nationalism, which often includes an attraction to Islam, but a subsequent decline in the 1970s when it seemed like black Americans were on the verge of prosperity. Then, in 1980, the economic condition of blacks began to worsen again. The recession of 1981 was a major depression in the black community, which experienced an unemployment rate double that of whites, and stimulated new interest in Islam.

"The appeal of Islam," says Shakur, "is its call for justice. And the only one you are accountable to is God alone. Islam is submission-- everything submits to God."

Louise Blake, Mustafa's mother, said she has raised seven children, and after their initial Baptist upbringing they were free to make their own life.

"I have people from all walks in my family--Catholic, Baptist, Methodist, you name it," Blake said. "When my son reached over to be a Moslem, I was not going to fault him. I enjoy listening to him talk about it, and how it came out of Africa and that sounds pretty good."