Félix Marie Henri Tilkin better known by his pen name Ivan Caryll, was a Belgian composer of operettas and Edwardian musical comedies in the English language. He composed (or contributed to) some forty musical comedies andoperettas. Caryll's career encompassed three eras of the musical theatre, and unlike some of his contemporaries, he adapted readily to each new development. After composing a few musical burlesques, his first great successes were made in light musical comedies, epitomised by the George Edwardes productions at London's Gaiety Theatre, such as The Shop Girl, The Circus Girl, The Girl from Paris, and A Runaway Girl. He continued to write musical comedies throughout the next decade, including such hits as The Messenger Boy, The Toreador, The Girl From Kays, The Earl and the Girl, The Orchid, The Spring Chicken, The Girls of Gottenberg and Our Miss Gibbs. He also wrote some operetta scores, such as The Duchess of Dantzic. After this, he moved to New York City where his post-war works, incorporating new fox-trot and one-step rhythms, included The Girl Behind the Gun (later a London hit as Kissing Time). At the peak of his career, he had the unparalleled distinction of having five musicals running at the same time in the West End.