Tom Crown, a professional trumpeter for over forty years, many with the Lyric Opera Orchestra of Chicago, produced his first trumpet straight mute in 1968.
The series of mutes for orchestral brass instruments which followed was quickly adopted by orchestras around the globe.
Since 2019 the complete manufacturing process has been carried out at the company’s own modern factory in Chicago.
French horn players often use a technique known as stopping—inserting their hand fully into the bell to block the air flow, producing a quiet, nasal sound. This raises the pitch by approximately one semitone, so the player must adjust by playing a semitone lower. The same effect can be achieved more reliably with a stopping mute, which may be transposing or, occasionally, non-transposing; this mute is the former and requires the player to play a semitone lower, as they would when hand-stopping.