In the late 1930s in Winona, Minnesota, the late Harold "Hal" Edstrom, his brother Everett "Leonard" Edstrom and their friend Roger Busdicker had formed a very popular dance band. Concerned that their conservative father wouldn't approve of using the family name for a band, Harold and Ev took parts of their names and called the band Hal Leonard. As leader of the Hal Leonard Band, Ev eventually became known as "Hal Leonard."

The company Hal Leonard was founded in 1947, after the Hal Leonard Band broke up. At the time, Ev started a music store using the Hal Leonard name while Roger and Harold were both directing award-winning high school bands in Winona. In those days, most school bands played serious literature, but Harold and Roger had the unique ability (because of their professional experience) to arrange "popular" music for school bands. Soon band directors across the US wanted their arrangements. They started to mimeograph copies and sell them. They realized that to successfully (and legally!) launch a new publishing company, they needed to license songs, so they ventured to New York's Tin Pan Alley in search of copyrights. What they got on their trip was an education in publishing and the rights to "I Wonder Who's Kissing Her Now," one of the most popular songs of the day. Eventually, many music publishers in New York were licensing Hal Leonard to do school band arrangements of their songs. Thus began their publishing business and an entirely new industry.