He was a descendant of Isaac Pasquier, from Poitou, France, who arrived in Nouvelle-France in 1665 as a soldier in the Carignan-Salières regiment.

Lavallée began his musical education with his father (Eli Grande), who taught him organ by age 11.

[4] Lavallée gave his first performance at Montreal's Theatre Royal (on Côté Street) on 28 February 1859 and later that year he was hired by Charles Duprez to play violin, cornet, and piano in a travelling minstrel troupe.

[5] With this company, the New Orleans Minstrels, Lavallée travelled through much of the United States in the years leading up to the outbreak of the Civil War.

[9] To celebrate St. Jean-Baptiste Day in 1880, the Lieutenant Governor of Québec, Théodore Robitaille, commissioned Lavallée to compose "O Canada" to a patriotic poem by Adolphe-Basile Routhier.

[11] As the result of the campaign by the Montréal-based music director of the Victoria's Rifles, Joseph-Laurent Gariépy, his remains were returned to Montréal and reinterred at Côte-des-Neiges Cemetery in 1933.