I have a theory that whether a Band Drum Major uses whistles or voice commands is based on the style of the band, DM preference, and director choice.
We see that many bands that use vocal commands have mace Drum Majors, and are typically Scottish or British style. The whistle command bands have usually American Mace, and Military Drum Majors.
Drum Majors using the whistle might also give attention vocal commands, and dismissal vocal commands.
I think the vocal command is used to assert authority, vs a whistle. With vocal commands (if executed loudly and correctly), the band gets a sense of an authority figure from the Drum Major. Everyone else (spectators, judges) see this Drum Major as "Oh man, look at this voice!" "That DM is IN CHARGE!".
My band uses vocal attentions and dismissals. Everything else is whistle. One notable difference, is our DM"s do not blow the whistle with a "TWEEEEEEEUUUUUUUEEEEET" style, rather with a straight "TWEEEEEEEEEEEEET" - "TWEET' "TWEET" "TWEET" "TWEET" blow.
We use baton signals to signal the band that we are turning left, right, around, stopping, etc. We also accompany those with whistle commands, because lets face it. Not all DM's are towering over the band. A good sized band might have trouble seeing the baton signal from the back/mid section. Whistles with signals are a great way to alert the band.
A band should not rely on a director or instructor to direct them while marching in competition. That is the Drum Majors job!
- I encourage all Drum Majors to visit this website for more information on whistle/vocal commands! This is a great website by Rick Wilson, and helped me through many questions!