If you went to a music hall in the UK prior to 1930 you might have seen one of these cornet players:
Kittie Stewart toured UK music halls during the First World War. Her unique selling point was that she could play the cornet and piano at the same time.
Captain T Jackellis
Sticking with the "playing two instruments at the same time" theme, Kittie Stewart toured for a while with a band featuring Captain T Jackellis - who billed himself as "King of the Cornets". Jackellis (his spelling, and presumably his surname) could play two cornets at the same time!
Evelyn HardyEvelyn Hardy had a long career as a cornet soloist and then as a trumpet player fronting her "Ladies' Radio Band".
Evelyn Hardy and her Ladies' Orchestra. Relayed from The Blenheim Gardens, Minehead
Trained by the late Captain William Short , the King's Trumpeter, Evelyn Hardy has had much success in the music-hall and concert world, both as a soloist and in ensemble. The band has developed from a dance combination into a straight orchestra, and tonight will show its versatility by playing both kinds of music. (Radio Times, 28 July 1933)
Evelyn eventually settled in Teignmouth, Devon, where she ran a music shop (Evelyn Hardy's Music Salon), taught music, and continued to play with her band at least until the late 1940's. Someone wrote a poem about Teignmouth Pier which includes this verse:
While Evelyn Hardy and her All Girls’ Band played
We listened and watched and were sometimes amazed
At the skill of the dancers who took to the floor
There was no way you could get us through the door. (source)
Some other interesting cornet players of this period from other web sites
Esperantoj Artisto (a duo, playing multiple cornets and a flugel)
Ruby Corrick (lady cornet player from New Zealand)