All that can presently (September 2023) be gleaned about Harry Knox from sheet music covers and by Internet searching is that he was presumably a British music hall performer who has been featured on just one work namely I Shall Blow My Whistle! (1910) music by Charles Collins, words by Fred Murray and published by Francis, Day & Hunter, London W.C.2, England
Billed as "The Lively Eccentric Comedian" on a poster dated 5th Deecember 1910 promoting a Tivoli show The Jolly Little Dutch Girl, he appeared with Miss May Moore Duprez.
Surfers are welcome to contribute any further information about this performer.