The impetus behind the inaugural march, which organizers call the first of its kind in New York City, might seem unlikely: the jazz pianist Mike LeDonne.
Mr. LeDonne, a fixture on the city’s jazz scene for decades, said he has been working for several years to create an annual Disability Pride Day and parade to shine a spotlight on people with mental and physical disabilities.
“Actually, she’s the reason for the parade,” said Mr. LeDonne, 58, pointing to his daughter, Mary, 10, inside their apartment in Hell’s Kitchen. She was on the floor, cradling a musical toy, and repeatedly pressing its buttons to hear a variety of tinny melodies.
Mary was born with Prader-Willi syndrome, a genetic disorder that has left her developmentally disabled and without speech. She is legally blind and often uses a wheelchair.