John was born in Scranton, Pennsylvania in 1955. His earliest teacher was his Aunt Claire, who taught him to play "The Dance of the Imp" at the tender age of seven. His first encounter with the music of Stravinsky sealed his fate as a composer. He studied at the University of Notre Dame with Priscilla McLean and David Isele, at University of Cincinnati College-Conservatory of Music with Jonathan Kramer and Alan Sapp, and has also studied privately in New York City with Dary-John Mizelle. Principal influences (besides the music of Stravinsky) include Messaien, Debussy, Copland, Britten, Berg, and the music of Japan, where he studied for a time as an exchange student.

Colligan served for 14 years as music director in several churches in the Cincinnati and New York City area. He taught music at Hunter College Elementary School, and is now chair of the music department and Director of Children's Theater at St. Hilda's & St. Hugh's School, an independent Episcopal school for children on New York City's Upper West Side.

Communication, craft and wonder are values which propel Colligan.  Communication is central in concert music today, where the goal of audience-building is paramount.  Craft, it goes without saying, honors the deepest spiritual necessities; without it, music conveys a lesser message.  Wonder is the crux of art.  Think of Diaghilev’s saying:  “Astonish me!” For John, a piece of music has failed unless it astonishes.