But cold, wet weather thwarted hopes of setting a new Guinness World Record.
The event was organized by Nez pour Vivre, a group aimed at raising money to help 18-to-30 year olds fighting cancer.
It featured performances by several Quebec musicians.
An official from Guinness World Records was on hand for the occasion.
The target was 17,000 people — more than the number gathered at an event in Australia in 2011.