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.
She is also highly sensitive to music and has an insatiable appetite for it, which has helped her learn, develop and interact with the world, said Mr. LeDonne. He was moved by his daughter to create a lively public musical procession that celebrates people whose distinctiveness is usually described in negative terms.
Mr. LeDonne said he enlisted as much volunteer help as he could to organize the parade, which is scheduled for July 12 and will proceed from Madison Square to Union Square. He has created a nonprofit organization and is holding a fund-raiser on Thursday featuring prominent jazz musicians, including Ron Carter, Benny Golson and Brad Mehldau.
Mr. LeDonne is also performing, and plans to bring his daughter.
The event, Jazz Legends for Disability Pride, will take place at the Quaker Friends Meeting Hall near Gramercy Park. The musicians, Mr. LeDonne said, are his friends and colleagues and are donating their performances.