The Harmon or Wah-wah mute was patented on July 14, 1925, by George Schlusselburg, a citizen of Germany living in Chicago. He assigned one- half interest to P.T.“ Paddy“ Harmon. Paddy Harmon was the owner of the Dreamland and Arcadia ballrooms. He was a millionaire, multi faceted promoter and business tycoon. He invested 2.9 million dollars in the Chicago Stadium in 1929. His interest in the Wa-Wa mute and his connection to George Schlusselburg are not known, nor is it clear who George Schlusselburg was. The association of Paddy Harmon with the Harmon mute, however, was fortuitous. Imagine a band leader telling his trumpet section, “Guys, don’t forget your Schluesselburgs tomorrow,” In 1929 George Gershwin, in his Rhapsody in Blue, used both a trumpet and trombone Harmon mute in prominent solos. A range of trumpet players from Clyde McCoy to Miles Davis, (without the cup) have been identified with the Harmon mute. Paddy Harmon was killed in an auto accident in 1930. No idea what happened to the mythical George Schlusselberg
The term of a US design patent is 14 years. It is non renewable, so when we started working on our version of the Wah-wah mute in 1970, the Harmon patent had long expired.
We were interested in making a somewhat larger Wah-wah mute, improving the intonation and freeing up the low register. John Howell, lead trumpet in the 50s with Woody Herman, Stan Kenton, Boyd Rayburn and others was my main tester. He was playing in the WGN Big Band with me. After trying many test samples we decided on what is now the Tom Crown Wa-Wa mute. It is purchased, and we hope liked, by about 1,000 trumpeters a year. We have not yet made a trombone Wah-wah mute. Maybe someday in the future, but the demand is small.