He began his music career at the age of nine as a vocalist and comedian with Leavitt's Bellringers, a company of entertainers that toured many of the larger cities of the United States.
Wheeler's Band was the first to publicly perform Bagley's "National Emblem March" in 1906.
This piece is played as a patriotic tune on Independence Day celebrations in the United States and features an excerpt from "The Star-Spangled Banner".
A theme from this march is popularly sung with the words "and the monkey wrapped his tail around the flagpole".
His brother Ezra M. Bagley (January 3, 1853 – July 8, 1886) was the first trumpeter in the Boston Symphony Orchestra from 1880 to 1884 and also composed marches for bands.