Joseph Nicholas Anthony Macerollo, OC is a Canadian classical accordionist, music educator and author. He was appointed an Officer of the Order of Canada in 2013 for his achievements as a musician, educator and promoter of the free bass accordion on the concert hall stage.

Accordions are a family of box-shaped musical instruments of the bellows-driven free reed aerophone type. The essential characteristic of the accordion is to combine in one instrument a melody section, also called the diskant, usually on the right-hand keyboard, with an accompaniment or Basso continuo functionality on the left-hand. The musician normally plays the melody on buttons or keys on the right-hand side, and the accompaniment on bass or pre-set chord buttons on the left-hand side. A person who plays the accordion is called an accordionist.