I think a whistle has many use. In sports during practice and even police officer use it, but those are the common whistle that I encounter. I never once thought about whistle that musician use in performing beautiful music but looking at the Grover-Trophy Slide Whistle photo (on the left side makes) me convince that it really is a good slide whistle perfect to use in orchestra. Only the talented and excellent craftsman can craft a durable, great intonation, great sound and highly responsive good slide whistle that mostly use in many commercial application and even professional orchestras where can achieve a glissando or trombone effect. It is impressive.