Male song sparrows from two areas in Quebec had repertoires of several song patterns, each one of which was generally made up of two repeated units, or syllables, plus unrepeated note complexes. Variability between individuals was large, but there was also some similarity: while most syllable types were sung by one individual only, some were shared with others in the population. The relative occurrence of the different syllable types was similar in two sites at Pare Cote Ste. Catherine but between Pare Cote Ste. Catherine and Mont St. Hilaire (separated by 23 mi) there was almost complete lack of similarity, which was taken as evidence that dialects existed. Birds from the less densely populated area at Mont St. Hilaire had slightly smaller repertoires of syllables and song patterns.