Is there a siffleur in the house?

If you were listening to the radio today and heard a new word - siffleur - referring to Ronnie Ronalde who has just died, you have not yet read the Five Leaves' book A Brief History of Whistling. Ronalde is of course covered in the book. A siffleur is a professional whistler. The female version is siffleuse, and our book was launched with a siffleuse, Sheila Harrod, who knew Ronalde, stealing the show. The book also retells John Gorman's story of Ronalde appearing on Sundays at a bar in Hackney, deserted during the week, but an upmarket bar with drag queens on Sundays. This was in the 1950s. Ronalde's whistling was popular in the 1940s and 50s, when he was regularly on the radio, had best-selling records and you could even by a Ronnie Ronalde whistling aid which looked like a polo mint but made of tin.
As far as we know, our book is the only book on the history of whistling!