For the next four days, the camaraderie and time-honored traditions usually shrouded in secrecy on leafy college campuses will be out in the open.
At the other end of Downtown, at the Westin Convention Center hotel, their sister group, the Alpha Kappa Alphas, will gather 1,300 strong.
Each group is having a four-day regional convention. It's unusual that they happen in the same town at the same time and the coincidence means an explosion of social, volunteer and career development activities for the black professionals and college students who make up the groups' membership.
By the time the dinners, workshops and boat rides are over, the groups' members are expected to drop more than $1 million into the city's coffers, according to the Greater Pittsburgh Convention and Visitors Bureau.
Sean Gibson, president of the local chapter hosting the men's event, thinks the conference offers a two-fold opportunity.
"It shows off all the best that Pittsburgh has to offer," and, he said, "the city has the chance to see what the energy and excitement of young African Americans can do for the city."
Gibson joined Alpha Phi Alpha while a student at Edinboro University of Pennsylvania in 1993 and became part of a group that celebrates its centennial next year.
In fact, there were eight national black fraternities and sororities, founded between 1906 and 1922, patterning themselves after the Greek-letter societies that had taken root on America's college campuses during the 1800s, and promoting a bond based on high ideals and common rituals.
Alpha Phi Alpha came first, in 1906. That was three years before the birth of the National Association for the Advancement of Colored People, when seven Cornell University men "binded themselves together" to survive a racially hostile environment. They went on to become physicians, engineers and educators.
Before long, chapters spread to other colleges and their reputation as achievers grew. Martin Luther King Jr., Duke Ellington and former Surgeon General Louis Sullivan are some of the leaders who belonged to the fraternity.
It was two years later, when 22 young women got together at Howard University to encourage high academics and community service, that Alpha Kappa Alpha was founded.
Since then, the organization has grown to include a global membership of 170,000, including such notables as Coretta Scott King, astronaut Mae Jamison and opera singer Marian Anderson. Eleanor Roosevelt was made an honorary member because of her support when Anderson was denied use of Constitution Hall for a concert.
Despite the claim to such illustrious members and pride in their volunteerism, on college campuses, black fraternities and sororities have a reputation for violent hazing, including severe paddling, kicking and slapping of new members.
Each of these groups has grappled with the issue and it's likely to dominate some sessions this weekend, where there will be calls to abolish what some see as a tradition but what others call unnecessary physical or psychological pressure.
"It's a major issue," said Gibson "and the organization has been cracking down on it for years because of all the lawsuits."
Much of the philanthropic work gets clouded by the negative, said Gibson, but the groups "are about so much more."
While in town, the AKAs will conduct "career day" service projects at Jake Milliones Middle and Westwood Elementary schools. With their brother group, sorority members will feed the hungry at the Jubilee Kitchen, Uptown, and care for seniors at Ebenezer Towers, Hill District.
"We're here to work," said Toni Kendrick, of Wilkinsburg, an AKA for 30 years and principal of Knoxville Elementary School.
For Kendrick, being in the sorority is all in the family. Her two sisters and her daughter belong to the group.
The conferences will bring in representatives from New York, Ohio, New Jersey, Delaware, Virginia and Michigan.
During the day, members will hunker down in committee sessions on budgets and rules and talk about progressive racial justice, a long-standing agenda for both groups. There will be a jobs fair and workshops on technology, health and welfare, education advancement and building corporate partnerships.
Much of the sessions are closed, but there are a few public events planned.
The largest includes tomorrow's Spirit of the Everyday Hero, an awards ceremony hosted by both groups.
The event will recognize local professionals and youths whose service has had a positive impact on the business, cultural, health or creative arts of the black community. It is free and will begin at 7 p.m. in the Spirit Ballroom of the David L. Lawrence Convention Center.
Tomorrow and Saturday, there will be the competitive "step shows" -- synchronized dance moves, drawing on African and black religious traditions -- that are perhaps the showiest element of black Greek life.