1884, American English, probably altered from earlier bazoo "trumpet" (1877); probably ultimately imitative (cf. bazooka). In England, formerly called a Timmy Talker, in France, a mirliton.
Kazoos, the great musical wonder, ... anyone can play it; imitates fowls, animals, bagpipes, etc. [1895 Montgomery Ward catalogue, p.245]
[1970s+; origin unknown; perhaps fr Louisiana French zoozoo, ''buttocks, ass''; perhaps kazoo, known in its standard sense fr the 1880s, suggested the anus in being tubular and emitting sounds]