I’m conscious that some readers may find the music featured in Choral March excessively pious (of course, some may find it not pious enough) If these readers are unfamiliar with this piece, I would beg them to reserve judgement until they listen ( I would always so implore, but especially in this case)
I recently discovered the extraordinary figure of Mary Lou Williams. The opening paragraph of her Wikipedia bio captures the breadth of her activities and influences:
Mary Lou Williams (born Mary Elfrieda Scruggs; May 8, 1910 – May 28, 1981) was an American jazz pianist, arranger, and composer. She wrote hundreds of compositions and arrangements and recorded more than one hundred records (in 78, 45, and LP versions). Williams wrote and arranged for Duke Ellington and Benny Goodman, and she was friend, mentor, and teacher to Thelonious Monk, Charlie Parker, Miles Davis, Tadd Dameron, Bud Powell, and Dizzy Gillespie.
Here is the blurb for about Williams:
She was ahead of her time, a genius. During an era when Jazz was the nation’s popular music, Mary Lou Williams was one of its greatest innovators. As both a pianist and composer, she was a font of daring and creativity who helped shape the sound of 20th century America. And like the dynamic, turbulent nation in which she lived, Williams seemed to redefine herself with every passing decade.
From child prodigy to “Boogie-Woogie Queen” to groundbreaking composer to mentoring some of the greatest musicians of all time, Mary Lou Williams never ceased to astound those who heard her play. But away from the piano, Williams was a woman in a “man’s world,” a black person in a “whites only” society, an ambitious artist who dared to be different, and who struggled against the imperatives of being a “star.” Above all, she did not fit the (still) prevailing notions of where genius comes from or what it looks like. Time and again, she pushed back against a world that said, “You can’t” and said, “I can.” It nearly cost her everything.
Back to Wikipedia for the turn in her life that led to her composing a hymn in honour of St Martin de Porres:
In 1952, Williams accepted an offer to perform in England and ended up staying in Europe for two years. When she returned to the United States she took a hiatus from performing, converting in 1956 to Roman Catholicism. Her energies were devoted mainly to the Bel Canto Foundation, an effort she initiated to help addicted musicians return to performing. Two priests and Dizzy Gillespie convinced her to return to playing, which she did at the 1957 Newport Jazz Festival with Dizzy’s band.
Father Peter O’Brien, a Catholic priest, became her close friend and manager in the 1960s. They found new venues for jazz performance at a time when no more than two clubs in Manhattan offered jazz full-time. In addition to club work, she played colleges, formed her own record label and publishing companies, founded the Pittsburgh Jazz Festival, and made television appearances. Throughout the 1960s, her composing concentrated on sacred music, hymns, and masses. One of the masses, Music for Peace, was choreographed by the Alvin Ailey and performed by the Alvin Ailey Dance Theater as Mary Lou’s Mass in 1971. About the work, Ailey commented, “If there can be a Bernstein Mass, a Mozart Mass, a Bach Mass, why can’t there be Mary Lou’s Mass?”  Williams performed the revision of Mary Lou’s Mass, her most acclaimed work, on The Dick Cavett Show in 1971.
In this lecture it is observed that Mary Lou Williams created some of the first pieces that explored jazz in a classical idiom. That is certainly true of the extraordinary Black Christ of the Andes (St Martin de Porres) and I will let the music speak for itself now: