Choirs, clergymen, and congregations honored the legacy of choreographer and modern-dance artist Alvin Ailey at nearly 40 churches around the city yesterday as part of the Alvin Ailey American Dance Theater’s 50th anniversary celebration. Revisiting Ailey’s spiritual roots, the choirs sang some of the gospels from his small-town Texas childhood that later inspired his best-known work, “Revelations.”

In the packed pews of Harlem’s Abyssinian Baptist Church sat a mix of church regulars, tourists — some of whom had to wait outside due to overcrowding — and members of the Ailey board of trustees, along with New York’s first lady, Michelle Paige Paterson, and artistic director of the Ailey company, Judith Jamison. Ms. Jamison, who danced with Mr. Ailey for 15 years prior to becoming artistic director, addressed the crowd. “Sometimes I ask myself, how in the world did that man get from Rogers, Texas, which you can barely find on a map, to where I stand today,” Ms. Jamison said. “But let me tell you, it’s no accident. The spirit of God and humanity speaks through us.”

The cathedral choir sang a soulful rendition of “I’ve Been ‘Buked” from “Revelations,” as 18 young church members wearing varying tones of plain, brown dress performed a simple composition of contractions toward earth and hopeful reaches toward heaven.

In 1958, when black dancers still had limited presence onstage, the 27-year-old Ailey created his own opportunity to work, gathering a group of 13 other black dancers to perform his “Blues Suite” at the 92nd Street Y.

“At the core of his existence was that an African-American cultural experience through dance could be accessible to all,” Ms. Jamison said in an interview before the church service. “Works like ‘Revelations’ are seen everywhere, and everyone understands because it has universal themes: trial, tribulation, turmoil, hope, happiness. Mr. Ailey was interested that everyone have a personal experience when they see the company, and that, because the dancers dance from a place from deep within, they make you feel differently and walk away from the wonderful place that is the theater just a little differently.”

During her almost 20 years as artistic director, Ms. Jamison has expanded upon Ailey’s efforts to reach out to all. Since Ailey’s death in 1989, his organization has developed an arts-in-education program that uses his “Revelations” as a teaching tool in classrooms across the country. Ms. Jamison has also helped develop yearly Ailey summer camps for school children and a bachelor of fine arts program in dance together with Fordham University.

At the Abyssinian church, Reverend Eboni Marshall drew upon her own formative years as a student in the Ailey/Fordham University B.F.A. program in a sermon.

“Alvin Ailey’s life and legacy, as embodied in these people here today, taught me how to stand up straight, how to push higher, how to go deeper,” Rev. Marshall said. “This wisdom stands head and shoulders over the rest: No matter how much my abdomen has eaten, no matter how sore my hamstrings are, no matter how late I stay out, no matter what the circumstances, the show must go on.”

“With Mr. Ailey it was always a prerequisite that we also teach and reach back and make children realize their creativity,” Ms. Jamison said. “I really just expanded and carried on some of things he started.”

Over the next 18 months, as part of the 50th anniversary celebration, Ailey’s legacy will take on a range of forms: the artist David Michalek has created video installation screens depicting slowed-down versions of larger-than-life Ailey dancers along the ground-floor windows of the Ailey studios on Ninth Avenue; Hallmark has produced a series of six Ailey greeting cards; the Library of Congress in Washington, D.C., opens an Ailey archive exhibit this May; an Ailey Barbie doll is due out this fall, and in June, the Ailey company returns to the Brooklyn Academy of Music for the first time in 38 years

Earlier this year Ms. Jamison announced her retirement as artistic director. She will leave the post in 2011, and ideas of a successor are thus far still vague.

“I have a three-year plan and we’ll see the end results of that plan at the end,” Ms. Jamison said. “I want this company to be around another 50 years, but I can’t say I’m looking for this, this, and this,” she said. “Otherwise, I could sell it to you in a bottle.”